A financial crimes unit formed by three major cryptocurrency firms announced Thursday that it has frozen more than $450 million in illicit digital assets since launching less than two years ago, as the broader problem of criminal activity in the crypto sector reaches unprecedented levels.

The T3 Financial Crime Unit—a joint initiative by stablecoin issuer Tether, blockchain network Tron, and analytics firm TRM Labs—said it has frozen the assets globally while deepening its collaboration with regulatory agencies to target crypto-related financial crimes.

The unit said it has supported investigations this year into crimes ranging from drug trafficking and exchange hacks to terrorist financing, North Korea-linked activity,…