Double Olympic champion Mo Farah has pulled out of the Sainsbury Birmingham Diamond League in the wake of doping accusations levelled against his coach, American Alberto Salazar.

Farah (pictured) left Birmingham for the US in a huff "to seek answers to my questions and get back to training".

The latest development follows a BBC investigative piece that alleges Salazar violated anti-doping rules and doped US 10,000m record holder Galen Rupp in 2002, when the athlete was 16 years old.

Salazar has been Farah's coach since 2011. Farah won the 2012 Olympics 5,000m and 10,000m gold.

However, there are no suggestions Farah doped.

Yesterday, Farah was visibly angry during a press conference ahead of today's IAAF Diamond League here in Birmingham, when asked about the allegations levelled against his coach.

"Salazar must clear his name so I can be free to run without stress," Farah said. He, however, announced today he was pulling out of the Sainsbury Birmingham Diamond League, a move that prompted the organisers to re-jig the timetable, which had the 1,500m event last.

PHYSICALLY DRAINED

"This week has been stressful and taken a lot out of me," he said in a brief statement. "I have not been able to focus properly on today's race. I feel emotionally and physically drained.

"I apologise to the people who bought tickets to come and watch me race and ask your understanding at this time," the statement read.

"I spoke to Alberto (on Friday), I got on the phone and said to him, 'Alberto, what's going on?' and he said, 'Mo, I can prove this to you - it's just allegations - I'll show you some evidence', and I said, 'Okay'," Farah added.

"I'm really angry at this situation. It's not fair, it's not right. I haven't done anything but my name's getting dragged through the mud," added Farah, who joined Salazar in 2011 and went on a year later to do the double in the 5,000m and 10,000m at the Olympics, and then went on to rubber stamp his dominance in the events with doubles at the 2013 World Championships and last year's European Championships.

"I'm a clean athlete. I'm against drugs 100 per cent and believe anyone caught should be banned for life."