Bob Van Voris and Chris Dolmetsch/Bloomberg News (TNS)

WASHINGTON — A Washington judge has overturned a decision to grant bail to two people accused of trying to launder billions of dollars worth of Bitcoin stolen in a 2016 hack of the Bitfinex currency exchange.

Late Tuesday, the judge granted an emergency request from the US government to continue to hold Ilya Lichtenstein and Heather Morgan in jail while the bail decision is reviewed. “The defendants are sophisticated cybercriminals and money launderers who pose a serious flight risk,” prosecutors said in their filing. The government said that while the majority of the stolen funds have been seized, there are several other virtual currency addresses that the government believes the couple control that hold approximately 7,506 Bitcoins, valued at over $328 million.

Lichtenstein and Morgan had been released on bail by a lower Manhattan judge on Tuesday evening, after being arrested at 7 a.m. in New York City. They are tried in Washington. The US government said it seized around $3.6 billion worth of cryptocurrency from the married couple, the largest financial seizure ever. The two allegedly conspired to launder 119,754 Bitcoins, currently valued at around $4.5 billion, stolen after a hacker broke into Bitfinex’s systems.

US Magistrate Judge Debra C. Freeman had set bail of $5 million for Lichtenstein and $3 million for Morgan. Both bonds had to be guaranteed by their parents’ houses. But prosecutors asked a Washington judge for an emergency delay to allow that court to consider whether Lichtenstein and Morgan should be freed. Chief Justice Beryl Howell agreed with the government on Tuesday evening in a one-page order.

The government initially asked the New York judge not to allow them to be released on bail. Each defendant faces a 20-year prison sentence, so they have the motivation to show up, a prosecutor told the judge in court. When the judge indicated she would set bail, the government asked that it be set at $100 million, an amount that one of the defense lawyers called “laughable”.

Lichtenstein, 34, holds dual American and Russian citizenship. He wore jeans and a gray shirt in the courtroom, his dark hair was slightly messy and he sported a paunch. Morgan, 31, appeared in court wearing a white hoodie, her long hair down. They both wore masks, like everyone else in the room, as required by the court.

They watched the magistrate as she read them their rights. None of them spoke publicly during the initial appearance. Their attorneys – they retained a separate attorney – spoke in court.

Morgan, who was born in Oregon and raised in California, has overseas ties, the prosecutor said in court. She has lived in Hong Kong and Egypt and is studying Russian, according to her social media. She is a journalist and economist and travels abroad for work, according to the government. Her father is a retired US government biologist and her mother worked as a librarian. Morgan’s parents were in the courtroom on Tuesday.

Lichtenstein moved to the United States at the age of 6 to escape religious persecution. He grew up in suburban Chicago, where his mother was a biochemist at Northwestern University. His father worked for Cook County. His parents were also willing to set up their house as surety.

They have been in a relationship since 2015, the government said.

Lichtenstein’s attorney told the New York judge that his client had not fled despite having been fully aware of the investigation for months, after being told in November by an internet service provider . His attorney also said there was no evidence against Morgan.

But prosecutors argued they should not be released, noting the defendants had used false identities in their crimes. Lichtenstein had a folder named “personas,” and there was a file on a computer with the name “Passport (underscore) ideas” with links to fake IDs and passports, according to the government. A search of their apartment found a plastic bag under the bed labeled “burner phones,” according to a prosecutor.

An attorney for the defendants, Anirudh Bansal, declined to comment on the case outside the Manhattan courtroom.