The FBI arrested a husband and wife on Tuesday morning, alleging they conspired to launder cryptocurrency stolen from the 2016 hack of virtual currency exchange Bitfinex, and said law enforcement has already seized over $3.6 billion (€3.1 billion) in cryptocurrency tied to the hack.
It represents the agency’s largest financial seizure ever, Deputy Attorney General Lisa Monaco said in a statement, adding in a statement that it shows cryptocurrency is "not a safe haven for criminals".
Ilya Lichtenstein, 34, and his wife Heather Morgan, 31, both of Manhattan, are scheduled to make their initial appearances in federal court Tuesday at 3:00 p.m. in the US District Court for the Southern District of New York.
The case was filed in a federal court in Washington DC.
The pair is accused of conspiring to launder 119,754 Bitcoin that was stolen after a hacker attacked Bitfinex and initiated more than 2,0000 unauthoriSed transactions.
Justice Department officials said the transactions at the time were valued at $71 million (€62 million) in Bitcoin, but with the rise in the currency's value, it is now valued at over $4.5 billion (almost €4 billion).
"As the complaint alleges, the FBI and federal prosecutors were able to trace the movement of Bitcoin from this hack," said Matthew Graves, the US Attorney for the District of Columbia.
He added that the money moved through a major darknet exchange tied to a host of crimes, as well as cryptocurrency addresses tied to child sexual abuse materials.
Tuesday's criminal complaint came more than four months after Monaco announced the department was launching a new National Cryptocurrency Enforcement Team, which is comprised of a mix of anti-money laundering and cybersecurity experts.
Crypto platforms have seen a number of hacks recently. Last week, Wormhole, a bridge linking the Solana and the Ethereum blockchains, was hacked and lost about $320 million.
Cybercriminals who attack companies, municipalities, and individuals with ransomware often demand payment in the form of cryptocurrency.
In one high-profile example last year, former partners and associates of the ransomware group REvil caused a widespread gas shortage on the US East Coast when it used encryption software called DarkSide to launch a cyberattack on the Colonial Pipeline.
The Justice Department was later recovered some $2.3 million (€2 million) in cryptocurrency ransom that Colonial paid to the hackers.