It is thought to be the first news of any of the girls since Boko Haram released a video purporting to show their forced conversion to Islam last May.

The 24 schoolgirls, who she says she was held with for three days last November, were physically well, she said, and were being coerced to cook for their captors, who numbered in their thousands. The girls were reportedly very tearful and homesick but had not been harmed.

“They were very emotional,” said Monica Sunday, a 20-year-old Christian woman (pictured below) who had been kidnapped by the jihadist group after her village, Kiva, in the far north east of Nigeria, had been twice attacked and then burned to the ground.

She spoke to us in a dusty informal camp for displaced people near the capital, Abuja, where she had recently arrived.

“None of the girls really talked very much,” she said. “They just cried and prayed and lamented for their parents. I comforted them and told them to have faith in God and that He would open a way for them so that their nightmare would be over.”

Monica, who was herself deeply traumatised by her own experience and lost her small baby, Abraham John, as she fled through the bush while making her escape, said the Chibok girls had remained true to their Christian faith. They wore simple head-coverings – not full hijabs – she said, but none was practising Islam.

Split up and dispersed

The Boko Haram insurgents have a brutal reputation for raping the women they abduct, but Monica insisted that the Chibok girls had not been sexually abused and that none of them was pregnant.

“The girls I was with were all in their mid-teens, some a bit younger, some older,” she said. “None of them was sick.” She did not know where any of the other girls, among the 219 still missing, were held. She also said that none had been forced into marriage. Monica knew about the kidnap of the Chibok girls before she herself was abducted.

“They divided them up. Some were taken to Gwoza [a town near Nigeria’s border with Cameroon, near to where Monica herself had been abducted]. Not all of them are held in one place.”

This is in line with earlier reports that the girls had been split up into smaller groups and dispersed across the region.

Monica says that the “room” in which she was held with the Chibok girls was a shanty-style lean-to, its roof just polythene sheeting.

After three days, she says she was moved to another part of the camp where she was held with more than 40 other women from across northern Nigeria, who, like her, had all been kidnapped.

“Among them was one particular woman who they beat until she was bleeding all over her body because she refused to convert to Islam,” she said. “She eventually succumbed,” she said, her head bowed. Monica said she had refused repeated attempts to force her to convert.

“They were really angry with me and shouted and screamed at me and called me ‘arney'” – an abusive term for “infidel” in the Hausa language. But she said that she had not been physically hurt by her captors. Her experience at their hands in the Sambisa camp, having been marched for two months through the bush, has left Monica shattered. “Every time I hear their name,” she said, “I shake with fear.”

She said that the Boko Haram commander in the Sambisa camp was called Ibrahim Shekau, who she described as “assistant” to Abubakar Shekau, the apparently deranged leader of the group. It is not known whether the two are related.

Impenetrable terrain

The camp, she said, was huge, and sprawled through almost impenetrably thick forest terrain. She said there were at least 1,000 women held captive there and thousands of rebel soldiers. “Most of the soldiers are out in the bush all the time, hunting others,” as she put it. They had guns and uniforms and many military vehicles, and there were access roads.

Monica added that these roads allowed Boko Haram to bring tankers, carrying drinking water, into the camp. She said there was enough food, mostly looted from nearby villages by the rebels. “They even have grinding machines,” she said. “We had rice and we had corn. No meat, but sometimes there was fish.”

It is known that there is military aerial surveillance of the Sambisa forest region, so the existence of many vehicles – including water-tankers – would suggest it would be possible to spot the camp from the air. I asked her whether she thought it would be possible for the Chibok girls to escape from Sambisa. “It would be very hard,” she said.

Monica made her escape when she was driven out of the camp into the bush at night with her baby, for reasons that were not clear to her. She found herself miles from anywhere and started walking east, towards Gwoza. The journey took her several days, without food.

Her baby died somewhere along the way and Monica, now completely alone, said she was unable to bury the child. “I had to just leave his body in the bush,” she said. She spoke quietly and matter-of-factly, but without obvious emotion.

Most of her family is in a refugee camp in neighbouring Cameroon. Her husband is in Lagos, where he has found work as a bicycle taxi-driver.

After reaching Gwoza, she says she kept walking all the way to Cameroon, where she tracked down her parents. She came to Abuja earlier this year with her younger brother, in the hope of meeting her husband, John, again.

Within the past two weeks, Monica says she was interviewed and debriefed by Nigerian military intelligence after her story was made known to the authorities. She says that after hearing her personal account, “the military people asked me many questions about the Chibok girls. They vowed to me they would go to the Sambisa forest as soon as they possibly could.”