Leading law firms representing HSBC and Hermitage Capital Management have been raided by Russian Interior Ministry officials in an attempt to link senior lawyers with an alleged tax fraud.

The raids, which took place at four offices in Moscow, including Firestone Duncan, a US firm, appear to have targeted lawyers seeking to recover three investment companies owned by HSBC that were allegedly stolen in a complex web of fraud.

According to Hermitage, the theft of the companies was conducted with the assistance of senior Interior Ministry officials and subsequently the stolen companies were used to defraud the Russian Treasury of $230 million (£124 million) in taxes previously paid by Hermitage.

William Browder, the chief executive of Hermitage Capital, who was barred from Russia in 2005 after conducting campaigns against corruption at leading Russian companies, including Gazprom, said the raids were evidence of the deteriorating rule of law in Russia.

“After we filed a criminal complaint notifying the Russian Government of a $230 million tax fraud against the state, the first thing the Russian police did was start attacking the lawyers who uncovered and reported the crime,” he said.

The raid at the offices of Eduard Khairetdinov, a lawyer acting for Hermitage, occurred on Wednesday evening, shortly after a package of documents was delivered to the office by courier. The ministry officers seized the package and confiscated papers, indicating that they were the founding documents of the three Hermitage investment vehicles used to conduct the alleged tax fraud.

According to Hermitage, these documents had not been seen since June 2007 when they were taken from the lawyer's office by ministry officials in the initial raid. They had been used to change the ownership and directors of the three Hermitage companies.

A bogus lawsuit was then initiated against the companies and later a claim was made to the Russian authorities demanding repayment of $230 million in taxes on the grounds that the companies had been bankrupted due to legal claims.

The package delivered on Wednesday indicated that it had been sent by “Alexander Strazhev”, who appeared as plaintiff in the bogus lawsuit against the Hermitage companies and Hermitage's London office was named as the return address. However, according to Hermitage, DHL records showed the package was delivered to a depot in South London.

Mr Khairetdinov has been summoned for questioning by the Interior Ministry in connection with the package. “They are trying to tie me, as Mr Browder's lawyer, to the extortion of $230 million from the state budget,” he said.

Three other law firms were raided by the officials as well as Firestone Duncan, where tax and accounting documents were seized.

Jamison Firestone, a partner in the firm, said that foreign investors were beginning to reconsider projects in Russia. He expressed surprise that so many people were turning a blind eye to the Hermitage case and the recent troubles at TNK-BP.

“I sit on the board of the American Chamber of Commerce and people say: ‘BP, that is a political matter, it's an exception',” he said.

“Well, I've got news for you. Everything is political and everything is an exception. There is nothing too outrageous.”

Formal complaints by HSBC to the Russian general prosecutor about the alleged theft of the Hermitage investment vehicles have failed to elicit any concern within the administration about the alleged criminal activities of Interior Ministry officials.

According to Hermitage, the General Prosecutor's office passed the complaint to an Interior Ministry official who is believed to have been involved in the theft.

In June, Hermitage found that the lieutenant-colonel who launched the original raids where the Hermitage company foundation documents were seized had subsequently joined the committee that is investigating the Hermitage affair.

Mr Browder said: “Each time we believe we have seen the worst of official harassment and corruption, we are unfortunately surprised. The situation continues to worsen and it sends a chilling message to all investors.”

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