The investigation, led by the AFP’s Criminal Assets Confiscation Taskforce (CACT), commenced in September 2018 following a tip-off from Luxembourg authorities about questionable Bitcoin activities.

The transactions were linked to a Queensland man previously convicted of hacking a gaming company in the US.

The investigation identified suspected links between the man and the theft of 950 Bitcoin from a French cryptocurrency exchange in 2013.

Although no criminal charges were brought, national laws on proceeds of crime empower the CACT to retain assets suspected to be crime-related, even when no prosecution occurs.

Last month, the District Court of Queensland ordered the man’s assets to be forfeited to the Commonwealth.

In July 2023, the CACT secured restraining orders against the waterfront property, a 2019 black Mercedes-Benz, and 24.99454224 Bitcoin, on grounds of suspected criminal connections.

The CACT said the assets were not commensurate to the man’s identifiable legitimate earnings.

They are estimated to be worth more than $4.5 million, with the Bitcoin worth more than $4 million of that.

Revenue from their sale will be put into a fund that supports crime prevention and law enforcement measures.

Since July 2019, the CACT has restrained more than $1.2 billion in criminal assets, including houses, cars, yachts, cryptocurrency, fine art, and luxury goods.