A spokesman for prosecutors told reporters on Tuesday that the investigation focused on financial statements submitted by Marian Banaś, who heads Poland’s central auditing office and who previously served as the country’s finance minister.
Paweł Sawoń, spokesman for the Regional Prosecutor's Office in the eastern city of Białystok, said that investigators were probing suspected irregularities in the official’s property declarations and tax returns, state news agency PAP reported.
He added that no charges have been pressed so far.
Poland’s ruling conservatives last week urged Banaś to resign after a TV exposé suggested the auditor lied about his income and had links to pimps.
Prime Minister Mateusz Morawiecki told reporters on Friday that he had read a classified report on Banaś by the Central Anti-Corruption Bureau (CBA) and expected him to quit.
But Banaś, who in the past headed Poland’s National Revenue Administration (KAS), has dismissed the allegations swirling around him as "lies."
He continues in his job and cannot be fired under the constitution.
His Supreme Audit Office (NIK) is Poland’s top state audit body tasked with monitoring public spending.