Sir Mo Farah is Great Britain's most successful track athlete in modern Olympic history but he has been keeping a secret for over 30 years.
The 39-year-old long-distance runner won the hearts of the nation when he powered to victory in the 5,000 and 10,000 metres at London 2012 before repeating the feat four years in Rio de Janeiro.
However in an astounding revelation during a BBC documentary, set to air on Wednesday, Mo Farah admits he is an illegal immigrant who was smuggled into the UK by traffickers at the age of nine.
