A teenager from Madagascar has spoken of how she was kidnapped, drugged and raped for two months after meeting a man she had spoken to online.

'Jenny', 17, from Antananarivo, the capital of Madagascar, had been talking to the 28-year-old on Facebook for six months, and when he asked, she agreed to meet him.

She spent the first two weeks in captivity unconscious, after which she remembers being repeatedly raped, abused and fed drugs to force her into submission and stop her escaping.

I had more than 310 friends on Facebook. I didn't know over a hundred of them. I just wanted to have many friends on Facebook,' Jenny, which is not her real name, said.

She accepted a friend request from a 28-year-old man she did not know, and the pair began chatting on the social network.

'My parents didn't know that I was talking to strangers on Facebook. The 28-year-old guy came and told me to follow him.'

Over the following six months, Jenny talked to her new Facebook friend a lot, and when she needed help she reached out to him.

She had failed an exam at school, and her teacher had told her he wanted more than £200 in exchange for giving her a pass - money Jenny simply did not have.

So she turned to her Facebook friend, and he agreed to help her.

'He kidnapped me and kept me locked in his house for two months. I was unconscious for two weeks.'I dreamt that my mother died so I tried to escape but I couldn't. I could never go out and he abused me. He raped me during these two months. I used to cry a lot after what he did to me.'I could not expect that the man whom I spoke to on Facebook for six months could have done such bad things to me.

'I really believed what he said when we spoke on Facebook, I did not realize that he might harm me when we met. I thought he was very kind.

Jenny was finally freed when a neighbour saw her at the abuser's house, and reported it to the police.

The police referred Jenny to a UNICEF supported help centre where Jenny received medical and psychosocial support and counseling.

She has been able to return to school, but complains of 'memory problems', and struggles to retain information.

'I am now more or less doing more or less ok now', she says.'Going back to school was ok but I have memory problems with the lessons I learn. 'I really don't know why it happened but when I learn the lessons, I remember nothing,'

The man was arrested and has since been charged with child abduction and sexual abuse and is awaiting trial.

Jenny's teacher who demanded payment for a passed exam has also been arrested.

While Jenny's is an extreme case, hundreds of thousands of teenagers around the world risk putting themselves in harms way by participating in risky behaviour online, a new UNICEF study has found.

The new report finds that adolescents appear confident with their own ability to stay safe, with nearly 90 per cent of interviewees believing they can avoid online dangers.

MailOnline