Romanowski faces 11 charges of misusing a “justice fund” earmarked to support victims of crime. Among the allegations leveled against him it is claimed that around 112 million złotys were funneled to the right-wing coalition that ruled Poland until the end of last year, and also to the Catholic church and the controversial priest Tadeusz Rydzyk.

It is also alleged that a further 200 million złotys were sunk into the election campaign of Sovereign Poland (Suwerenna Polska), a Catholic nationalist party led by former Justice Minister Zbigniew Ziobro which was a junior partner in the previous government.

The most serious charge, however, contends that Romanowski was part of “an organized criminal group”.

After his immunity was lifted, the lower house of parliament passed a motion to detain Romanowski.

Romanowski’s lawyer, Bartosz Lewandowski, had previously stated that his client would voluntarily appear at the National Prosecutor’s Office. However, concerns were raised that Romanowski could potentially obstruct justice or destroy any incriminating evidence. These concerns have now been allayed with Romanowski’s detention.

“MP Marcin Romanowski was detained today at the request of the prosecutor conducting an investigation into irregularities in the Justice Fund,” the National Prosecutor's Office said in a statement.

It added: “Immediately after receiving the documentation, the prosecutor issued a decision to press charges against Marcin Romanowski. During the investigation into irregularities in the Justice Fund, the prosecutor obtained evidence allowing him to charge Marcin Romanowski with committing 11 crimes.”

Romanowski has denied the accusations made against him, and has declared himself the target of a political witch hunt.

Since assuming power, the current ruling coalition has doubled down on its promise to bring to account those it deems guilty of abusing power.