Aleksej Besciokov, a Lithuanian citizen and Russian resident, was arrested in the southern state of Kerala on Tuesday, India’s top investigative agency said.

According to the US Justice Department (DOJ), he was one of the administrators of Garantex, a Russian cryptocurrency exchange, and was responsible for reviewing and approving its transactions.

Besciokov is in custody and has not yet made a statement. Garantex could not immediately be reached for comment.

Besciokov was “residing in Russia”, according to DOJ’s recently-released indictment, and it is unclear when and why he came to India.

India’s Central Bureau of Investigation (CBI) said in a statement that it issued a provisional arrest warrant against himat Washington’s request.

Besciokov will now be produced in a court in Delhi, it said. It is not clear when he will be extradited to the US.

The United States, in coordination with Germany and Finland, had taken down the online infrastructure used by Garantex, the DOJ said last week.

It added that Garantex processed at least $96bn (£74.10bn) in cryptocurrency transactions since 2019 and that it allegedly received hundreds of millions in criminal proceeds, which were then used to “facilitate several crimes”, including hacking, ransomware, terrorism and drug trafficking.

The DOJ also accused the Lithuanian national of violating sanctions and operating an “unlicensed money transmitting business”.

Last week, US officials charged Besciokov along with the exchange’s Russian co-founder Aleksandr Mira Serda with money laundering.

Garantex was sanctioned by the US Treasury Department in 2022.

But soon after, Besciokov and other administrators “redesigned” its operations to “evade sanctions” and induce American businesses into working with them, DOJ said.