US-businessman Bill Browder has said the UK government is "appeasing" Russia by refusing to implement stronger sanctions against the country.
"I have seen in real life the appeasement which goes on on a day to day basis with relation to Russia," he told MPs on the foreign affairs committee this afternoon.
Back in 2004, Browder was the largest foreign investor in Russia. The American business owner's investment fund, Hermitage Capital Management was worth $4.5bn at the time.
He is now fighting for justice for his "murdered" lawyer, Sergei Magnitsky, who uncovered the theft of $23m from the Russian treasury by a criminal enterprise. Russian officials accused Browder of the murder.
He helped to pass a law in the US which restricted visas to the US for those Russian individuals who were involved, and has called on the UK to follow suit.
"Since the act was passed, the government has refused to enact a similar piece of legislation here. Allowing people involved... to come to this country," he told MPs.
Browder called for assets to be frozen, travel to the UK to be banned, and for the names of those involved in the murder to be made publicly available.
Some were critical of his stance, saying it would not help the UK's relationship with the former Soviet state.
"It's possible to have a mature relationship with Russia where you don't allow their individual torturers and murderers to come into your country and continue to talk to them about issues of strategic importance," Browder argued.
He also said the UK needed to take more action to deal with "dirty money" that was being laundered through the country.
"Britain is in the worst... or second worst position in terms of enforcement of money laundering rules," he said, adding that London was the "money-laundering centre of the world".
Browder told MPs:
If the law enforcement agencies decide to prosecute and they fail, they end up paying the costs... of the winner. As a result... nobody will ever take the economic decision to launch any case unless they are 100 per cent sure they are going to succeed.
He has suggested eliminating this cost, which would "change the nature of investigations" into the issue.
Browder was strongly opposed to the lifting of sanctions against Russia, and explained that without them, it would give Vladamir Putin a "green light to do terrible things".
He argued that the Russian dictator would have gone further into Ukraine and could have "begun to play around with the Baltic states" if sanctions has not been imposed.
"He is absolutely terrified by these sanctions... this is causing him great problems," he said.
The businessman pulled no punches attacking Putin and the Russian regime.
"Inviting Russia to an anti-corruption summit would be like inviting Pablo Escobar to an anti-drugs summit. Any pledge that Russia makes is of zero influence," he said.
They cheat in sports, they do cyber attacks, they cheat in business, in politics, at the UN. There is no area where they are not corrupt.
Browder said that Putin gets "a cut from every crime" and that the entire state was "a facade of the normal functioning of civil society."
He is a Mafia boss, he can do all the crimes he wants inside the country… without any risk to his position. He doesn’t have to worry about going to jail… being impeached, being thrown out by the electorate as the elections are all a fraud.
He also encouraged businesses not to do business with Russia.
"This is a place that is not suitable for business for any civilised person," he added.