PRAGUE (AP) — Czech Republic Justice Minister Pavel Blažek resigned from his post over a bitcoin-related scandal on Friday.

Blažek was under fire from the opposition after his ministry accepted a donation of bitcoins and sold them for about 1 billion Czech koruna (more than $45 million) earlier this year.

Blažek said that he wasn't aware of any wrongdoing, but didn’t want the four-party coalition government led by Prime Minister Petr Fiala to be harmed by the scandal. Fiala said that he appreciated his resignation and believed that Blažek acted with goodwill.

Blažek was a close ally of Fiala in the government, and also in his conservative Civic Democratic Party. It's not clear who might replace him.

The issue focused on the fact that the bitcoins were donated to the ministry by a person who was previously convicted of drug dealing and other crimes. The opposition has accused Blažek of possible money laundering, because it wasn't clear where the bitcoins came from. It was also not clear why the person donated the bitcoins to the ministry.

The issue has been investigated by the police organized crime unit. The scandal took place just months before the Oct 3-4 parliamentary election. The main opposition ANO (YES) party led by former populist Prime Minister Andrej Babiš is predicted to win the vote.