British long-distance running star Mo Farah will no longer work with long-time coach Alberto Salazar but has denied the split is related to doping allegations surrounding the Oregon-based guru, it was reported on Monday.

In an interview with The Sun newspaper, Farah, the four-time Olympic champion over 10,000 metres and 5,000 metres, said he was ending his association with Salazar because of a move back to Britain.

The 34-year-old Somalia-born star began training with Salazar in 2011 at his Oregon Project camp in Portland, and won his first world title the same year in the 5,000 metres at the Daegu World Championships.

Salazar’s training base however has been the subject of intense scrutiny from the United States Anti-Doping Agency. A leaked USADA report this year asserted that Salazar had likely violated drug protocols, later denied by the coach.

Farah, who has repeatedly denied involvement in doping, told The Sun the allegations involving Salazar were not behind his decision.

“I’m not leaving the Nike Oregon Project and Alberto Salazar because of the doping allegations,” he told the paper. “This situation has been going on for over two years, if I was going to leave because of that I would have done.

“As I’ve always said, I am firm believer in clean sport and I strongly believe that anyone who breaks the rules should be punished. If Alberto had crossed the line I would be out the door but USADA (US Anti Doping) has not charged him with anything. If I had ever had any reason to doubt Alberto, I would not have stood by him all this time.”

Farah, who has retired from track running to concentrate on the marathon, said family reasons had driven the move. “I’m leaving simply because my family and I are moving back to London,” he said. We all loved spending our summer here and Tania and I realised how much we have missed spending time with our friends and family – and the kids are so happy here, too.

We want the kids to grow up in the UK. It’s the right thing to do for my family. But both Nike Oregon Project and Alberto are based in the USA, so it just would not be possible to continue our relationship from London.”