Mo Farah's estranged brother Ahmed said he fears being killed if he is deported to his native Somalia after serving a prison sentence.
The 27-year-old, who no longer speaks to his Olympic champion sibling, said he is on the brink of being sent back to the war-torn country following his conviction in 2011 for his role in a knife raid.
The Farahs have lived in the UK since Mo was eight and Ahmed was two, although their relationship broke down as the athlete's career took off.
He told the Sunday Mirror: "I can't go back to where Mo and I were born - it is too dangerous.
"I'm scared I would end up dead. I feel there's no hope for me.
"I am afraid for my life. I have no roots in Somalia. People would kill me because I'm different. They would not class me as their own.
"They'd see me as an outsider, somebody whose family ran away, and they don't want to welcome me back."
Farah said his tattoos also make him an outcast among those who follow Sharia Law and is now praying on a Home Office climbdown.
He said: "I'd have to walk the streets (in Somalia). I'll just get attacked. People are going to detect I'm not from there - the way I talk, my swagger, everything about me."
The Home Office said it does not comment on individual cases.