Marcin Romanowski, from the previous right-wing coalition government of the United Right, was arrested by the Internal Security Agency on Tuesday after parliament approved his pre-trial detention and waived his immunity.

Prosecutors were pushing for an extension of his detention period, citing the gravity of the 11 charges.

These included granting unlawful subsidies from the Justice Fund, a special reserve established by the justice ministry to aid victims of crime. According to prosecutors, this fund was used to finance the interests of Sovereign Poland, a minor coalition partner of the Law and Justice party.

The money was used for various unrelated purchases intended to boost support for Sovereign Poland politicians in their respective constituencies, prosecutors say.

But late on Tuesday evening, Romanowski was released following an emergency meeting ordered by the court.

Romanowski said that the legal grounds for the court’s decision were his holding “immunity as a member of the Parliamentary Assembly of the Council of Europe [PACE].”

He added that he would take “legal actions” against prosecutors and those who, at the request of the Minister of Justice, prepared legal judgments which served as a basis for detaining him despite his valid immunity.

Earlier on Tuesday, PACE’s president, Theodoros Roussopoulos, wrote a letter to the Lower House speaker, Szymon Hołownia, in which he listed a number of Romanowski’s rights and appealed for the suspension of the court proceedings until PACE lifts his immunity.

Roussopoulos said in the letter that the Council’s session lasts a whole year, and the Polish authorities, after the Sejm waived Romanowski's immunity, should have submitted an adequate application to the European bodies before launching their own proceedings.