British Olympic star Sir Mo Farah has said he continues to live with the "sadness and trauma" of being trafficked to the UK as a child to work as a slave.
The four-time Olympic champion recalls being taken away from his family in Djibouti by a woman he had never met and told he was to live with relatives in the UK.
But when he arrived in the UK, the woman told him he was no longer to be called by his birth name Hussein Abdi Kahin and was now Mohammed Farah.
"When I came with that woman, I was told your name is not Hussein it's Mohammed," he told BBC Radio Four.
"Coming through the airport, she was saying 'Mohammed, Mohammed, Mohammed'. I was just being told constantly 'remember that, remember that and that is all'."
He had been given a list of contacts from his family, but the woman ripped it up in front of him and he was forced to live with her and work as a slave looking after her children.
"When I was leaving, all my family had their details written down for me," Sir Mo said, before a documentary about his true identity, The Real Mo Farah, was broadcast on BBC iPlayer at 6am UK time and at 9pm on BBC One on Wednesday.
"Then, right in front of me, the lady took it off me and ripped it up and said 'don't say anything, this is it'. Pretty early on I knew my life would be different living with that lady.
"I wasn't allowed to play with other kids, I was not allowed to be myself, I had to cook, clean, change diapers.
"It was tough for me and all I ever wanted as a kid was to have my parents or someone who cared for me. Early on I knew that no one was going to be there for me, so I learnt to block it out. I still feel sadness and trauma."
London's Metropolitan Police has said it was assessing the allegation that Sir Mo was trafficked, after his mother sent him away to escape civil war in their native Somalia.
He was encouraged to speak out now by his wife and children — one shares his real birth name Hussein — after burying the truth for decades.
"My reaction was heartbreak and sadness for him," his wife Tania told the BBC.
"I just pictured nine-year-old Mo being so helpless and vulnerable and I was so angry at the people who did that too him and put him through that. I do not know how anyone can live with themselves.
"I knew he was always carrying that hurt and pain and that gave him that edge and driving force to go on to achieve great things."
Sir Mo, 39, revealed his suffering after asking his PE teacher, Alan Watkinson, for help.
He confided in Mr Watkinson about his true identity, his background, and the family he was being forced to work for. He later gained UK citizenship, but under his new name.
"Alan did go to social services. We did report it, we did tell them exactly what was my name ... so we went through the right channels, but I don't know why nothing was ever done," he said.
The British Home Office has ruled out taking any action against Sir Mo over his citizenship status.
"He is a sporting hero, he is an inspiration to people across the country," a spokesman for Prime Minister Boris Johnson said.
"It is a shocking reminder of the horrors that people face when they are trafficked. And we must continue to clamp down on these criminals who take advantage of vulnerable people."
Sir Mo told the BBC he was not in touch with the woman who forced him into slavery — and said he "does not want to be".
Nadhim Zahawi, the UK Chancellor of the Exchequer, told LBC that the family who trafficked Sir Mo should only be investigated if the athlete wished it.
"If Mo Farah doesn't want it investigated, then it shouldn't be," he told LBC's Nick Ferrari at Breakfast.
"I think we need to talk to Mo Farah because he is a great man, he's been through an extraordinary life, and what a harrowing tale.
"I thought my journey from an immigrant boy from Baghdad to this great country of ours was an extraordinary story, but what he has had to endure, in my view, should make him the priority for all of us.
"The police need to talk to Sir Mo Farah first before they do anything else."