The General Prosecutor’s office said a decision to drop the fraud investigation into Sergei Magnitsky was annulled and a request to resume the probe sent to the investigative arm of the Russian interior ministry.

“We have sent a letter to the interior ministry investigative committee,” a spokeswoman for the General Prosecutor’s office told AFP.

The decision follows a Constitutional Court ruling allowing criminal cases to be pursued against suspects who are already dead and was met with outrage by the Hermitage Capital fund in which Magnitsky worked.

“This represents a clear abuse of the law and due process”, a company representative said in a statement.

The prosecutors’ move comes 20 months after the death of the 37-year-old lawyer and just days after Moscow imposed a visa blacklist in response to Washington’s decision to ban entry to Russian officials linked to the case.

The Russian lawyer worked for what was then Moscow’s largest Western hedge fund. But its US-born founder Bill Browder had repeated run-ins with the authorities and was eventually denied entry to Russia.

Magnitsky was arrested and jailed shortly after he went public with claims that Russian tax and interior ministry officials had used a complex scheme to claim some $235 million in taxes paid by the fund.

The attorney was charged with the very crimes he claimed to have uncovered and investigated by the same police officials he named in the tax case.

Browder’s fund has since led a global campaign to introduce sanctions against Russia for failing to punish officials it believes were responsible for the lawyer’s death and illegal arrest.

Washington also outraged Moscow last week by banning visas for an unspecified number of Russian officials linked to Magnitsky’s investigation and treatment in jail.

The Russian foreign ministry warned that it would take “adequate measures” against the United States and announced the introduction of its own list of unnamed officials who allegedly mistreated Russians.