Jirikovsky, identified by local media as the donor of 468 bitcoin, valued at roughly $45 million at the time, to the justice ministry, was taken into custody at a property in Breclav, according to Echo24.
The donation, made earlier this year, was accepted by then-Justice Minister Pavel Blazek without verification of its origins.
Blazek resigned in May amid mounting criticism after media revealed the funds came from Jirikovsky, a convicted darknet operator previously jailed for drug trafficking.
An audit commissioned by Blazek’s successor, Eva Decroix, concluded in July that the ministry should not have accepted the gift due to the major risk that it constituted proceeds of crime.
Prosecutors said Thursday the current investigation concerns “acts to clarify the case as well as measures to secure persons and property,” adding no further details would be released to avoid jeopardising the proceedings.
The scandal prompted a no-confidence vote in June that the government of Prime Minister Petr Fiala narrowly survived.
Opposition party ANO has since called for further ministerial resignations, including Finance Minister Zbynek Stanjura.
Decroix has pledged to publish an expanded timeline of the case this week, comprising more than 8,000 entries, as scrutiny intensifies ahead of October’s parliamentary elections.