(BLOOMBERG) - Russian President Vladimir Putin suggested the FBI has been drugging a whistle-blower it's protecting after he disclosed a massive state-run doping programme that led to Russia being barred from the 2018 Winter Olympics.

"He's working under the control of the American special services, what kind of substances are they giving him so he says what they need?" Putin said at his annual press conference on Thursday (Dec 14) in Moscow, in answer to a question about Grigory Rodchenkov, the former head of Russia's anti-doping lab, who is now in a witness-protection program in the US.

The International Olympic Committee has said that it considers Rodchenkov's testimony about Russian doping to be credible.

Putin, who decided against boycotting the Games to allow Russian athletes to compete individually under a neutral Olympic flag in Pyeongchang, South Korea, admitted the accusations had some truth to them.

"We're to blame ourselves. We gave them an excuse," he said.

But Putin, who has denied any state-backed programme, insisted that doping is widespread in other countries.

Putin said the issue was being "whipped up" for political reasons to influence the country's March 2018 presidential election, in which he's seeking to extend his 18-year rule for another six years.

The World Anti-Doping Agency has concluded that Russia ran a doping scheme involving about 1,000 athletes from 2011 to 2015.

The programme was organised after Russia finished in 11th place with just three gold medals at the 2010 Winter Games in Vancouver, its worst performance since the collapse of the Soviet Union.

Putin has invested heavily in international sports competitions, including the US$50 billion (S$67.3 billion) 2014 Sochi Winter Games, the most expensive on record, to boost national pride.

Russia topped the medals table in Sochi but the team has since lost that status after being stripped of 11 of the 33 medals it won as a result of doping violations.