Tens of millions of pounds of "dirty" Russian money is being laundered through the UK, MPs have been told.

The UK authorities are refusing to investigate evidence of tens of millions of pounds of "dirty" Russian money being laundered through British firms and banks, MPs have been told.

Former hedge fund boss Bill Browder said that, over the past five years, he had lodged six complaints with law enforcement agencies relating to 30 million US dollars (£20 million) of stolen funds - but in each case they had refused to act.

Giving evidence to the Commons Home Affairs Committee, Mr Browder - who became a leading anti-corruption campaigner following the death of his lawyer Sergei Magnitsky in a Russian prison cell in 2009 - said there was a "general political feeling" people did not want to "rock the boat".

"Every single time we have filed a complaint, nobody has responded. They have always found excuses not to investigate," he said.

Mr Browder said that the money coming into the UK was linked to a 230 million US dollar (£160 million) tax refund fraud on his Russian Hermitage fund which Mr Magnitsky had uncovered before his death.

But while 11 other countries - including the United States, France and Switzerland - had opened criminal cases into the stolen funds, in the UK the Metropolitan Police, the Serious Fraud Office, the National Crime Agency and its forerunner, the Serious Organised Crime Agency, had all refused to investigate.

"I think this country is levitating off the flow of dirty money," he said.

"If that money was stopped, I think that certain people would find themselves without businesses and I think those people have some political influence. I can't explain it any other way.

"I have been to France, I am working very intimately with the French police, I am working with the Department of Justice, I am working with the Luxembourg police.

"I think there is a general political feeling that you don't want to rock the boat. So many people benefit from that dirty money here, it is a politically toxic issue to address.

"If there are a lot of businesses that are effectively surviving off the back of this money that wouldn't survive otherwise and they have friends in high places - these people are very close geographically to this House here - they're going to say 'Don't do that'."

Mr Browder said that he believed the total sums being laundered through the UK ran into the "hundreds of billions of dollars".

"There has been an orgy of spending on luxury goods - properties, yacht charter, couture dresses," he said.

Much of the spending had concentrated around Belgravia, Knightsbridge, South Kensington districts of London - while properties had been bought up in the "fanciest parts" of the city including St John's Wood, Hampstead and Chelsea.

He added: "If they open up a UK company for example and use then it for money laundering at a UK bank, the next destination will say that money has come from Britain which is a legitimate, normal country.

"This is a perfect cover for laundering money because we don't investigate it in this country, we don't prosecute and it appears legitimate."

A spokesman for the National Crime Agency said that it treated allegations of money laundering with the "utmost seriousness".

"We have received material from Hermitage Capital which is now being actively reviewed. For operational reasons it will not be possible to confirm details of any investigation that may result," the spokesman said.