The United States has seized over $30 million in cryptocurrency stolen by North Korean-linked hackers Lazarus from the popular online game Axie Infinity, crypto intelligence firm Chainalysis said on Thursday.

The company said in a blog post it played a role in the recovery with U.S. law enforcement and other crypto organizations, without naming them, in the first ever recovery of stolen cryptocurrency by a North Korea hacking group.

Chainalysis and North Korea's mission to the United Nations did not immediately respond to requests for comment. The FBI did not immediately respond to a request for comment.

The seizures represent about 10% of the total funds stolen in March from Ronin Network, a sidechain built for the play-to-earn game Axie Infinity, Chainalysis said.

Ronin said in March hackers stole about $615 million in cryptocurrency.

"We estimate that so far in 2022, North Korea-linked groups have stolen approximately $1 billion of cryptocurrency from DeFi protocols," Chainalysis said. He was referring to decentralized finance protocols, an umbrella term for financial services offered on public blockchains.

The U.S Department of Treasury in May sanctioned virtual currency mixer Blender, saying it was used in the laundering process for the Axie Infinity heist.

The Treasury Department in April also linked Lazarus to the attack.