(Bloomberg) -- The U.S. seized about $3.6 billion in Bitcoin stolen during a 2016 hack of the Bitfinex currency exchange -- the largest financial seizure ever -- and arrested two people, the Justice Department said. 

Ilya Lichtenstein and his wife, Heather Morgan, were detained Tuesday morning and are scheduled to appear at federal court in Manhattan in the afternoon, the Justice Department said in a statement. The two allegedly conspired to launder 119,754 Bitcoin stolen after a hacker breached Bitfinex’s systems. 

“Today’s arrests, and the Department’s largest financial seizure ever, show that cryptocurrency is not a safe haven for criminals,” Deputy Attorney General Lisa Monaco said in a statement. “In a futile effort to maintain digital anonymity, the defendants laundered stolen funds through a labyrinth of cryptocurrency transactions.”

Bitfinex is the exchange affiliated with the world’s biggest stablecoin, Tether. At the time of the hack, the digital currency haul was estimated at about $71 million, the Justice Department said. The department said the total value of stolen Bitcoin is now worth about $4.5 billion. 

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According to DOJ, the couple used sophisticated techniques, including “using fictitious identities to set up online accounts; utilizing computer programs to automate transactions, a laundering technique that allows for many transactions to take place in a short period of time; depositing the stolen funds into accounts at a variety of virtual currency exchanges and darknet markets and then withdrawing the funds.” 

Lichtenstein, 34, and Morgan, 31, also funneled the money through AlphaBay Marketplace, which was shut down in 2017, to hide their transactions. Some of the money was cashed out through Bitcoin ATMs. Some was used to buy NFTs and gold. They even used the money to buy a Walmart gift card.

In August of 2016, Bitfinex reported a security breach and halted all trading, withdrawals and deposits. The company later disclosed in a blog post some of its users had their Bitcoin stolen, and that it had reported the theft to law enforcement. 

Lichtenstein and Morgan face up to 20 years in prison for the money laundering charges they face. In addition, they face an additional sentence of up to five years for conspiracy to defraud the U.S., according to the Justice Department statement. 

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