Perched on a throne adorned with cattle horns, the voodoo priest warns the housewife knelt in front of him of the deadly consequences of defying his powers.
'If you cheat on your husband, you will suffer for it, both you and the man you cheat with,' he says, wagging a gnarled finger. 'Defy the shrine and it will come and kill you.'
Just in case she has any doubts, High Priest Godspower Ojoduma shows her an photo album full of corpses, their limbs twisted and stomachs grotesquely bloated.
'You see them?' he says. 'That one was a witch, that one a thief, that one a liar. All sinners. All dead.'
This bloodthirsty ceremony, witnessed by MailOnline, is an oath-taking ritual for the ancient slave god Ayelala, one of the most feared of all Nigeria's voodoo or 'ju-ju' deities.
Rituals: Nigerian women tricked into sex work in Europe are subjected to black magic rituals by voodoo shaman who say the gods will come to kill them if they try to escape Pictured: A voodoo priest in Benin City, Nigeria. He is not suspected of being involved in trafficking
Black magic: Some voodoo priests force women to swear an oath to ancient slave god Ayelala, a feared Nigerian 'ju-ju' deity. Some wives are given a spell to stop them from being unfaithful Pictured: A shaman cuts a chicken's head during a ritual. He is not involved in trafficking
For hundreds of years, potent magic has been used to enforce everything from debt collection and land disputes through to marital infidelity. Pictured: A priest drains slits a chicken's throat.
But in the 21st century, she has acquired a chilling new role in a very modern social problem - the trafficking of sex slaves to Britain and Europe.
As the ruthless trade has escalated in the past decade, Nigerian trafficking gangs have begun evoking Ayelala's powers to terrify local women into doing their bidding.
The gangs bring thousands of young Nigerians into Europe every year, luring them promises of jobs in shops or hair salons, then forcing them into prostitution when they arrive.
To ensure they do not run away, they make them swear oaths to Ayelala before they leave Nigeria, often forcing them to provide clippings from their pubic hair as an 'offering'.
Such is the fear that voodoo inspires that many of the victims prefer to remain in sex slavery rather than disobey.
To see the sex trade's sinister alliance with black magic first hand, MailOnline travelled to poverty-stricken Benin City in southern Nigeria, home to an ancient African kingdom where voodoo priests are still widely revered.
Sex trafficked: A woman told how she was lured to Italy by a 'madam' who paid the €1,000 fee for a smuggler to take her across the Sahara and the Mediterranean Before she went the madam took her to a shrine dedicated to 'Shango', a Thunder God. Pictured: A shrine in Nigeria
She told MailOnline: 'A lady trafficker made us cut clippings from our fingernails and hair and put them on top of the shrine, and we lay down in front of it.' Pictured: Blood drained from a chicken and poured onto an 'offering'
When she arrived in Italy, she was taken to the northern city of San Torino, made to wear skimpy clothing and ordered to work in a brothel. Disgusted, she escaped and was reassured by a local priest the black magic spell was fake. Pictured: Bowl of water and chicken's blood
West Africa was once also the major market for transatlantic slaves and today, in a chilling echo of that role, Benin City has become the main hub for trafficking African prostitutes to the streets of London, Rome and Paris.
Such is the scale of the problem that local anti-trafficking charities believe that most young women will be approached at some point by a trafficker.
While most end up in Italy, because of its proximity to the Mediterranean smuggling routes, hundreds also find their way every year to Britain - home to Europe's largest Nigerian diaspora.
At Mr Ojoduma's temple in Benin City last week, MailOnline watched him perform a fidelity ritual on a housewife whose husband had taken her there on suspicion of having an affair.
Despite the gory threats he issued, Mr Ojoduma insists that Ayelala's oaths are never used for evil purposes.
But a victim, 27, told MailOnline how she was lured to Italy by a Benin City 'madam' who paid the €1,000 fee for a people-smuggler to take her across the Sahara and the Mediterranean.
To see the sex trade's sinister alliance with black magic, MailOnline travelled to poverty-stricken Benin City, southern Nigeria, where voodoo priests (pictured) are still widely revered. The priest in this picture is not involved in trafficking
Benin City has become the main hub for trafficking African prostitutes to the streets of London, Rome and Paris. Madams pay traffickers to take the girls, but put a spell on them to prevent them from escaping when they arrive. Pictured: A voodoo shrine in Benin City
Before she went, however, the madam took her to a shrine dedicated to 'Shango', a voodoo Thunder God.
'Before I went on the journey I was taken to a shrine with three other women,' sjhe said.
'A lady trafficker made us cut clippings from our fingernails and hair and put them on top of the shrine, and we lay down in front of it.
'We were also made to drink a glass of schnapps and rub white powder in our faces, so that nothing bad would happen to us before we reached Italy.
'Then we had to swear at the shrine before Shango. We were told that if we didn't pay back the money we owed the madam, Shango would come and kill us by sickness.'
She travelled across the Sahara to Libya and then by boat to Sicily, where she spent a month in a refugee camp before henchmen of the trafficking gang smuggled her out.
They took her to the northern city of San Torino, where she said the madam had promised her a job in a shop. Instead, she was handed skimpy clothing to wear and ordered to work in a brothel.
'When I arrived in Torino they told me to buy body cream to freshen up and look good and made me wear a short skirt,' she said.
'Then they took me to what looked like a hotel and I saw other women dressed in little clothing. It was only then that I realised I was there for prostitution. I was forced to sleep with a man twice, and felt very, very bad, so I ran away.
Around 30,000 women are believed to have been trafficked to Europe in the last two decades, more than 90 per cent of them from Benin City and surrounding Edo State. Pictured: A woman uses a headless chicken to perform a ritual. She is not involved in trafficking
One woman trafficked to the UK told how she was bathed in goat's blood and warned that if she ever spoke of the ritual, she would be struck dead by a thunderbolt. Pictured: A dead chicken used as a sacrifice
Another victim Joan was trafficked at 17 and deported from Italy at 22 after being the subject of a ritual at the hands of a ju-ju priest like the one, pictured above, cutting a goat's head off
'I was terrified that Shango would come and get me, but I met a local pastor who reassured me and brought me home.'
Joan, a Nigerian woman who was trafficked at 17 and deported from Italy at 22, told of her ritual at the hands of a ju-ju priest.
'He cut off my hair, my armpit, my private parts, my nose...then he took my picture,' she said.
Another woman anonymously revealed how she was tricked into sex slavery.
'Only when I got to Europe, the madam introduced me to prostitution. I had to work for her until I had paid her back,' she said
Nigeria's National Agency for the Prevention of Trafficking in People (NAPTIP) claims that many curses used for sex trafficking in Benin City are done in Ayelala's name.
Shango is another one of hundreds of deities found in Benin City, which is home to hundreds of voodoo shrines, most of them in makeshift temples in the city's shantytown sprawl.
Traditionally, they have been used for benign purposes such as healing and resolving domestic disputes. But because of their all-seeing reputation, their powers are also now sought by traffickers seeking to control people from a distance.
Voodoo influence has already surfaced in a number of reported trafficking cases in Britain, including one in 2013 where a girl from Benin City ended up in a brothel in Birmingham. Before her journey, she was bathed in goat's blood, and was warned that if she ever spoke of the ritual, a thunderbolt would strike her dead wherever she was in the world.
In another case in Cardiff in 2014, Lizzy Idahosa, 26, was jailed for eight years after being found guilty of running a brothel ring where Nigerian women had eaten snails and snakes in pre-trafficking rituals.
While no single deity dominates the trafficking trade, locals in Benin City and NAPTIP itself frequently cite Ayelala, whose red-coated followers are regarded with particular fear.
In a demonstration of how traditional beliefs blend with Christianity here, Ayelala devotees wear scarlet gowns decorated with white Christian crucifixes, and hold their ceremonies in a temple complete with church-style pews. But that is where the similarities end.
Outside Mr Ojoduma's temple, goats and chickens are kept ready for sacrifice in a slaughter room at the back of the priest's throne, while a sign bans menstruating women from entering.
The temples' front wall, meanwhile, is decorated with hundreds more photographs of victims of Ayelala's wrath - from alleged 'witches' and 'wizards' through fraudsters, adulterers and car thieves.
Such is the dread she inspires that even the sight of an Ayelala hat or cloak is enough to frighten people.
Joan, pictured, revealed: 'He cut off my hair, my armpit, my private parts, my nose...then he took my picture.'
Another victim, pictured, said she was tricked into slavery. 'Only when I got to Europe, the madam introduced me to prostitution. I had to work for her until I had paid her back,' she said
'There is one old woman who regularly right down the middle of the main road through town with an Ayelala hat on,' said one Benin City resident. 'Normally she would get run over, but all the cars choose to drive round her instead.'
Ten years ago, when the local market was looted after accidentally being set ablaze, a local Ayelala priest also decreed that anyone who has stolen goods should return them immediately. Overnight, large numbers of missing items returned.
Mr Ojoduma holds court along with his wife most mornings, sat beneath a gallery of framed certificates declaring him to be both a Justice of the Peace and a member of the Nigeria chapter of the 'World Successful Herbal and Medical Practitioners'.
He claims to have recently cured a Nigerian woman from London who had come to him with sickness.
Bizarrely, those who take oaths before him must bring a 'communion' to drink in the form of a bottle of strong liquor, either Johnnie Walker whisky or Seamen's Schnapps, a popular local spirit.
Asked about Ayelala's role in trafficking, he added: 'Sometimes people do come and ask, but I always turn them down. There are plenty who bring Ayelala's name into disrepute, but I have nothing to do with them.'
In another case in Cardiff in 2014, Lizzy Idahosa, 26, was jailed for eight years after being found guilty of running a brothel ring where Nigerian women had eaten snails and snakes in pre-trafficking rituals. Pictured: A hut in Benin City used for such ceremonies
Sister Bibiania Emenaha runs a local Catholic order that looks after trafficked women who have been returned to Benin City.
She said that frequently, women went to Europe knowing full well that they would be involved in prostitution, but that the voodoo rituals were still used to ensure that they repaid their debts to the traffickers.
A trafficker who paid €1,000 (£900) for a woman to be smuggled to Europe could often expect up to €30,000 (£27,000) in repayment.
'The women are afraid not only for themselves, but for their families and friends,' she said. 'They think that if they disobey what they swore in front of that juju, no matter whether it is Shango or Ayelala or another, it will start manifesting itself.'
'The older people here will tell you that prostitution is an abomination in their culture, but unfortunately, every family struggles to send their daughters abroad to work. Most are poor and are interested only in the money, not how they earn it.'
Last month at the UN annual summit in New York, Theresa May called for greater international efforts to fight sex slavery. She has also announced that £35m from the UK aid budget would be spent on tackling the trade, with £5m earmarked for Nigeria.
According to figures from the National Crime Agency, some 244 of the 2,340 possible trafficking victims by British officials in 2014 were from Nigeria - a 31 per cent increase on the previous year.
Figures from the National Crime Agency show 244 of the 2,340 possible trafficking victims by British officials in 2014 were from Nigeria - a 31 per cent increase on the previous year. Pictured: Nigeria's National Agency for the Prevention of Trafficking in People (NAPTIP) HQ
But Kevin Hyland, a former head of the Met Police's Human Trafficking Unit, who is now Britain's independent Anti-Slavery Commissioner, said the true figure could be much higher than that.
Mr Hyland told the MailOnline: 'Sadly, there is a now cultural acceptance in places like Benin City and Edo State that a daughter will be trafficked to Europe to earn money.
'We think there could be anything up to 1,000 women being trafficked into the UK every year now, some ending up in prostitution, others in forced labour, and I put that down partly to the impunity the trade has had.
'We need to realise that what happens in Nigeria has an impact in Britain, otherwise we'll just be picking up the pieces.'
