More than $1bn (£772m) in Bitcoin linked to the notorious Silk Road website has been seized by the US Department of Justice (DoJ).
Earlier this week, crypto-currency watchers noticed about 70,000 bitcoins being moved from an account believed to be linked to the illicit marketplace.
Silk Road was an online black market, selling everything from drugs to stolen credit cards and murderers-for-hire.
It was shut down by the US government in 2013.
The sum is the largest amount of crypto-currency seized to date by the Department of Justice.
On Thursday, US Attorney David Anderson confirmed that the officials had seized the crypto-currency assets.
"Silk Road was the most notorious online criminal marketplace of its day," he said in a statement.
"The successful prosecution of Silk Road's founder in 2015 left open a billion-dollar question. Where did the money go?
"Today's forfeiture complaint answers this open question at least in part. $1bn of these criminal proceeds are now in the United States' possession."
The Internal Revenue Service's Criminal Investigation unit said it used third-party company to analyse Bitcoin transactions that had been executed by Silk Road.
This led it to an address belonging to "Individual X", who is alleged to have hacked the funds from the marketplace.
Law enforcement officers in turn took control of the sum on 3 November, and the DoJ claims the funds are now subject to forfeiture.
"Criminal proceeds should not remain in the hands of the thieves," said IRS special agent Kelly Jackson.
In 2015, Bitcoin seized from a different wallet associated with Silk Road was sold at auction by the US government.
Silk Road creator Ross Ulbricht is currently serving two life sentences in prison after being found guilty of money laundering, computer hacking, and conspiracy to traffic narcotics.