Raphael Satter, Sarah N. Lynch

WASHINGTON (Reuters] – A husband and wife were arrested Tuesday by the FBI. The couple are charged with conspiring to conceal cryptocurrency that was stolen in the Bitfinex 2016 hack.

This is the Justice Department’s largest ever financial seizure. Deputy Attorney general Lisa Monaco stated that this action was a “not safe haven for criminals.”

Ilya Lightenstein, 34 and Heather Morgan, 31 respectively, will make their first appearances at federal court in Manhattan on Tuesday.

This case was brought before a Washington federal court.

After Bitfinex was attacked by hackers, the pair were accused of conspiring in order to launder 119.754 bitcoin.

Justice Department officials claimed that at the time, transactions were worth $71 billion. But, with currency value rising, they now have a market cap of over $4.5 Billion.

Matthew Graves (the U.S. attorney for the District of Columbia) stated that “as the complaint alleges”, the FBI and federal prosecutor were able trace the Bitcoin movement from this hack.

The money was also moved via a darknet platform that is linked to many crimes and cryptocurrency addresses related to child sexual abuse material.

The criminal complaint filed Tuesday came four months after Monaco had announced that the department would launch a National Cryptocurrency Enforcement Team. This team is made up of cybersecurity and anti-money laundering experts.

Many ransomware-wielding cybercriminals demand cryptocurrency payments to victims, cities and companies.

One high-profile case last year was when former associates and partners of the ransomware company REvil caused widespread gas shortages on the U.S. East Coast. The group used DarkSide, an encryption program called DarkSide, to launch a cyberattack on the Colonial Pipeline.

Colonial’s ransom to hackers of cryptocurrency cost $2.3 Million was recovered by the Justice Department.