World class athlete and Olympic champion Mo Farah arrived in Britain at the age of 9 and was forced to do menial work in exchange for food.

This included housework and childcare. “If I wanted food in my mouth,” he said.

Farah, 39, was born in Somalia and his original name is Hussein Abdi Kahin. His name was changed to Mohamed Farah to facilitate his travel on a fake document by an unknown woman.

Farah said that upon his arrival in the United Kingdom he was taken to her house in Hounslow in West London and all information about his relatives back home was destroyed. He was not even allowed to go to school until he was 12.

“For years I just kept blocking it out, but you can only block it out for so long,” he said in a BBC documentary.

“Often I would just lock myself in the bathroom and cry. The only thing I could do to get away from this situation was to get out and run.”

His ex-form teacher Sarah Rennie said that he came to school “unkempt and uncared for” and that he spoke very little English and was an “emotionally and culturally alienated child.”

Farah was later placed in a foster home in the Somali community after his physical education teacher Alan Watkinson contacted social services and helped him find a foster family.

He confided in Watkinson about his true identity, his background and the family he was being forced to work for.

After that he said, “I felt like a lot of stuff was lifted off my shoulders and I felt like me. That’s when Mo came out-the real Mo,” said Farah.

“I had no idea there were so many people who are going through exactly the same thing that I did. It just shows how lucky I was.

“What really saved me, what made me different was that I could run.”

Watkinson later assisted him in obtaining British citizenship under the name Mohamed Farah which was granted to him in July 2000.

Barrister Allan Braddock said that Mo’s nationality was technically “obtained by fraud or misrepresentation”. Legally the government can remove a person’s British nationality if their citizenship was obtained through fraud.

However a Home Office official told BBC news that it would not take action over Mo’s nationality as it was assumed that a child was not complicit when citizenship was gained by deception.

“Basically the definition of trafficking is transportation for exploitative purposes. In your case, you were obliged as a very small child yourself to look after small children and to be a domestic servant. And then you told the relevant authorities, “that is not my name”. All of those combine to lessen the risk that the Home Office will take away your nationality.”

Mo said that he wanted to tell his story to challenge public perceptions of trafficking and slavery.

The woman who brought him to London has been approached by the BBC for comment but she has not responded.