LONDON (Reuters) - Russia has asked Interpol for the seventh time to arrest Bill Browder, a London-based Kremlin critic who leads a campaign to punish Russian officials for the 2009 death of his lawyer Sergei Magnitsky, according to a letter seen by Reuters.

FILE PHOTO: Businessman Bill Browder speaks after the coroner ruled that Russian businessman Alexander Perepilichnyy probably died of natural causes outside his home in 2012, after the inquest concluded at the Old Bailey, in London, Britain, December 19, 2018. REUTERS/Henry Nicholls/File Photo

Once the biggest foreign money manager in Moscow, Browder has become one of the most vociferous Western critics of Kremlin chief Vladimir Putin, Russia’s preeminent leader since 1999.

Interpol’s Commission for the Control of Files wrote to Browder’s lawyers to say that Russia’s National Central Bureau had requested his arrest for charges including deliberate bankruptcy and tax evasion.

“The NCB of Russia has authorized the Commission to disclose to you its wish to request police cooperation for your client through an INTERPOL diffusion to arrest,” Interpol said in a letter dated Jan 21, 2019.

Russia casts Browder as a criminal. Browder casts Russia as a criminal state. Russia has repeatedly asked Interpol to arrest Browder, who was sentenced in absentia by a Russian court to nine years in prison for deliberate bankruptcy and tax evasion.

Interpol has rejected the requests six times. Browder says he is the victim of a vendetta by corrupt officials in the Russian state and denies all the charges.

Such is Browder’s notoriety that Putin even suggested to U.S. President Donald Trump last year in Helsinki that Russian officials be allowed to question him for allowing associates to earn $1.5 billion without paying any proper Russian tax.

Interpol’s eight-person Commission, which includes a Russian lawyer previously involved in drafting Russian state requests for assistance in pursuing Browder, will consider Russia’s request on April 15-19.

“It is envisaged that the NCB’s request should be studied by the Commission during its 108th session which will take place 15 to 19 April 2019,” the letter said.

American-born Browder, who made millions in Russian markets, has lobbied Western governments to adopt “Magnitsky Acts” to impose sanctions on Russian officials for corruption and rights abuses.

“Something needs to be fixed at Interpol if dictators can go back unlimited times to chase their enemies with bogus warrants,” Browder said on Twitter.