The whistleblower at the centre of the Russian doping scandal has told the BBC he is also aware of “extremely suspicious cases” involving British athletes.

Grigory Rodchenkov, the former head of the Moscow anti-doping laboratory, has been living in hiding in the United States since fleeing Russia in late 2015.

Having seen former colleagues die in suspicious circumstances, Rodchenkov’s current location is a secret and he is protected by America’s Federal Bureau of Investigation.

The 59-year-old was disguised for a recent television interview with US broadcaster CBS and for this interview with the BBC he is seen in a ski mask and dark sunglasses.

Asked if he was sorry about his role in a state-sponsored doping conspiracy that sabotaged London 2012 and Sochi 2014, Rodchenkov apologised to athletes from Britain and elsewhere for helping to cheat them out of medals.

“I’m especially sorry that I contributed and wrongly used all my knowledge and experience against all the clean athletes in the whole world, and that’s why I’m sitting here and telling you truth about what happened that time,” he said.

But when asked if he believed British sport had a doping problem, he said: “Honestly? Yes.

“I don’t tell now during (the 2018 Winter Games) in front of TV, but I have several extremely suspicious cases in British sport.”

Considered to be an expert in his field, Rodchenkov was invited by the International Olympic Committee (IOC) to work in the London laboratory that was used during the 2012 Games.

The Russian told the BBC it would be the “worst decision” if the Russian Olympic Committee’s suspension was lifted by the IOC to allow the country’s athletes to march in Pyeongchang’s closing ceremony as a full Russian delegation.

As a result of Rodchenkov’s remarkable allegations being corroborated by several investigations, the IOC suspended Russia in December, which meant their team has competed as “Olympic Athletes from Russia” in Pyeongchang and not been allowed to use the Russian anthem or flags in ceremonies so far.

It is widely believed that the IOC was all set to lift that ban in time for the closing ceremony, although two further Russian doping cases this week may have changed that plan.

Rodchenkov also told the BBC that the IOC and international sports federations are not interested in clean sport and huge reforms are needed.

He also made it very clear he believes his life would be in grave danger if the Russian authorities found his location and he claims the doping conspiracy was directed from the very top of the Russian establishment.

“It’s impossible to do on my own,” he said. “I absolutely followed orders. It was teamwork. FSB (the Russian security service) was involved when we had to control co-ordination.

“(Deputy Prime Minister Vitaly Mutko) knew absolutely everything, and he reported to the President. I know he reported to (Vladimir) Putin – he told me that. Putin is denying. It’s the usual situation.”