Sir Mo Farah has admitted he lied about his background and his name is not real. The four-time Olympic champion, 39, previously claimed to have joined his dad in the UK, but he was actually killed in the Somalian civil war. Farah, real name Hussein Abdi Kahin, has told a BBC TV documentary he was trafficked to the UK to work as a servant, and now fears losing his UK citizenship. Married dad-of-three Mo said: “There’s something about me you don’t know. It’s a secret that I’ve been hiding since I was a child. “I’ve been keeping it for so long, it’s been difficult because you don’t want to face i…