Double Olympic champion Mo Farah claims doping allegations against coach Alberto Salazar are “killing” him personally but admits he would sever all ties with the American should he be found guilty.

The middle-distance runner insists it is not fair he is being accused by association, insisting he is “100% clean”, but believes Salazar is entitled to be treated as innocent until found otherwise.

On hearing of the allegations, Farah flew out to his Oregon training base to demand answers and has welcomed investigations by UK Anti-doping and USADA.

“I am not on anything, trust me,” he told Sky Sports News.

“To be labelled something you are not and labelled a cheat is not fair and right: if I am a cheat prove I am a cheat or leave me alone. Prove I am crossing the line.

“Let’s get to the bottom of this. It is killing me, killing my family.

“UK Anti-doping and USADA need to get on top of this and deal with it properly as it is overshadowing athletics.

“They are just allegations. If there is wrongdoing I will be the first person to run (away) but you have to give people a chance in life and the benefit of the doubt.”

UK Anti-Doping confirmed on Monday it is investigating the doping allegations surrounding Salazar, who has vehemently denied the claims.

Farah admits he was stunned when the allegations came to light and it preyed on his mind so much he pulled out of Birmingham’s Diamond League meeting at the last minute.

Having done so he immediately jumped on a plane to quiz Salazar in Portland.

“I was shocked. I couldn’t believe what I saw. I am the first person to say ‘Look, what’s going on?’ I wanted answers,” he added.

“I work so hard for what I do. It has taken me half of my life to achieve what I achieved and for people to think I am taking a shortcut is not right. I am 100 per cent clean.

“I want to continue winning medals but I want people to know I am 100 per cent clean and am not on any drugs.

“This picture of me as a cheat is not right, it’s not fair. Why me?

“I said ‘You need to assure me’. He said ‘Mo, I am working on this, I will come out and disprove these allegations. These are just allegations and I can prove this to you’.

“I believed in him. He (now) needs to prove it to the public and people.

“I want those people (making allegations) to go to the right authority — not the media where words get twisted — and I am glad UK Anti-doping and USADA are looking at the investigation.”

Farah reiterated, however, that should Salazar be found guilty he would not hesitate to cut all ties immediately.

“Alberto has coached me and helped me; there is no question I have won medals with Alberto,” he said.

“But if he has crossed the line and is proven to have done so then I am out, trust me. Why would I be there?”