Giertych said the possible crime concerned former prime minister Mateusz Morawiecki, among others.

Donald Tusk's pro-European government, which took power in December, has vowed to hold to account those it accuses of abuses of power or negligence under the previous administration.

PiS, which led the previous nationalist government, has repeatedly denied accusations of wrongdoing.

Lawmakers heard on Friday about an "official omission, which led to Poland's irretrievable loss of the advance payment from the National Reconstruction Plan in the amount of 4.7 billion euros".

Under the previous administration, Poland had billions of euros of recovery funds frozen due to a dispute with the European Union over judicial independence and media freedoms. Amid the dispute, Warsaw did not apply for an advance payment, which would have been independent of rule of law criteria.

PiS spokesperson Rafal Bochenek said the complaint to prosecutors was unjustified and showed hypocrisy on the part of the government.

"Today, the prosecutor's office is being used for political purposes," he told Reuters by telephone. "If anything, the prosecutor's office should investigate how... Tusk and many others influenced EU institutions to block funds for Poles that should have been paid many months ago."

(Reporting by Alan Charlish, Anna Wlodarczak-Semczuk; Editing by Kirsten Donovan and Christina Fincher)