The crypto industry’s “criminal whales” are making a big splash.

According to a new report from Chainalysis, criminal whales – defined as wallets containing at least $1 million worth of crypto, that have received 10% or more of their funds from illicit addresses – accounted for nearly 4% of the total number of high value wallets last year.

Kim Grauer, director of research at Chainalysis, told CoinDesk the findings were noteworthy because the presence of fewer, larger targets demonstrates the potential for law enforcement seizures and the recouping of stolen funds.

“It allows us to say ‘this is the amount of money that is seizable should [the whales] be the target of an investigation,’” Grauer said.

The report comes one week after a couple accused of laundering the proceeds of a 2016 Bitfinex hack were arrested at their New York apartment, and a crypto wallet containing $3.6 billion in bitcoin was seized by government officials.

Read more: Federal Judge Releases ‘Razzlekhan,’ Orders Other Bitfinex Hack Laundering Suspect to Remain in Jail

The seizure of funds connected to the Bitfinex hack took a massive chunk out of the estimated $11 billion worth of funds with known illicit sources held by criminals at the end of 2021.

The Bitfinex hack laundering suspects’ case mirrors much of Chainalysis’ findings about large-scale crypto criminals.

Chainalysis’ research indicates that stolen funds dominated the total of “illicit funds” held by criminals last year, accounting for a whopping 93%. Darknet market funds accounted for $448 million, scams for $192 million, fraud shops for $66 million and ransomware for just $30 million.

And, like the alleged Bitfinex launderers, Grauer said the growing balance of criminal whale wallets indicates liquidity issues.

“If you’re a criminal whale, and you’re holding a lot of money, and there’s all these groups of people who are tracing funds, I suspect you have a major liquidity problem,” Grauer said.

“Maybe you’re waiting for a technological solution that you’re comfortable with, maybe you’re just holding it until you really need to cash out, but if you’re holding large quantities of illicit funds I think you’re probably aware that you have a difficult task ahead of you if you want to convert that to fiat currency,” Grauer added.

The report also highlighted a new time zone analysis technique developed by Chainalysis that provides insight into the location of criminal whales.

According to the report, UTC time zones 2, 3 and 4 – which include major Russian cities including Moscow and St. Petersburg – are believed to contain the most criminal whales.

Grauer stressed that, while the analysis is far from conclusive (time zones only show latitude, not longitude, meaning that the criminal whales could also be in parts of Africa or the Middle East), it’s a strong indicator of Russian criminal whale activity.

“Maybe this is someone not based in Russia, who just does business with Russia,” Grauer said. “But this is genuinely a stronger signal than I was expecting to get out of the analysis.”