The US seized more than $3.6 billion in Bitcoin stolen from the Bitfinex exchange in 2016, US Justice Department announced on Wednesday.

Deputy Attorney General Lisa Monaco stated it was the biggest financial seizure ever for the Department. "Today's arrests, and the Department's largest financial seizure ever, show that cryptocurrency is not a safe haven for criminals. In a futile effort to maintain digital anonymity, the defendants laundered stolen funds through a labyrinth of cryptocurrency transactions," Monaco said.

Arrests were also made in Manhattan, where federal law enforcement detained Ilya Lichtenstein and his wife, Heather Morgan. Lichtenstein and Morgan are accused of trying to launder the stolen 119,754 BTC from the exchange. They are facing charges of money laundering and conspiracy to defraud the United States, which carry a maximum penalty of 20 years and 5 years respectively.

"Today, federal law enforcement demonstrates once again that we can follow money through the blockchain, and that we will not allow cryptocurrency to be a safe haven for money laundering or a zone of lawlessness within our financial system," Assistant Attorney General Kenneth Polite Jr. said in a statement.

Bitfinex, a cryptocurrency exchange owned by iFinex Inc. was hacked in August 2016, when a hacker made 2000 unsanctioned transactions, moving the stolen crypto assets to a digital wallet connected to Lichtenstein. The total value of the haul was $71 million at the time of the hack - it increased to $4.5 billion 5 years later, the Justice Department said.

Some of the money was cashed out and used to buy NFTs and gold. The Justice Department has returned most of the stolen BTC to the exchange. Furthermore, they plan to establish a court process for victims to reclaim the stolen Bitcoin.