The probe, launched by prosecutors in the south-western city of Świdnica, will determine whether there are grounds for a full criminal investigation.
It follows the publication, by the website wPolityce.pl, of an extract from Skąd się wziął Karol Nawrocki? ("Where Did Karol Nawrocki Come From?") – a book-length interview with Nawrocki conducted by historian Andrzej Nowak – ahead of the memoir's official release.
In the extract, Nawrocki – then a candidate backed by the opposition Law and Justice (PiS) party – recalls a "moment of terror" after a campaign rally in the town of Ząbkowice Śląskie on 15 May 2025.
He says he lost consciousness on the campaign bus and woke to find aides standing over him, with his suit and the vehicle covered in vomit after several minutes of violent convulsions.
Nowak, the book's co-author, has suggested someone tried to poison Nawrocki to knock him out of the race, at a point when his eventual victory already looked likely, even raising the possibility of an assassination attempt.
Nawrocki said he had earlier been warned by security staff that greeting supporters by kissing women's hands could be a way of poisoning him, but continued the practice regardless.
Prosecutors in Świdnica said they were checking media reports that Nawrocki's health had suddenly deteriorated and that he had briefly lost consciousness, and that this "may have resulted from the administration of substances endangering his life or health."
No ambulance was called at the time.
Zbigniew Bogucki, head of the presidential chancellery, told reporters in parliament this week that the situation had been "secured in keeping with the rhythm of the campaign" and that Nawrocki had "focused on the campaign" rather than seeking medical attention.
Pressed repeatedly on whether he believed a poisoning attempt had taken place, Bogucki said only: "I do not know. The services must clarify this."
The claims appear to have surprised figures within Nawrocki's own camp.
Several PiS politicians told news outlet Wirtualna Polska they had learned the full details only in the past few days and doubted such an incident could have stayed secret for a year.
Michał Dworczyk, an MEP who helped organise the campaign stop, confirmed the bus had halted with its windows covered but said at the time he had not known why.
Former Prime Minister Mateusz Morawiecki, of PiS, suggested the "ruling camp" could "go to extremes" against opponents, while cautioning he had yet to read the book himself.
The government has called for answers.
Deputy Interior Minister Czesław Mroczek said the incident sounded serious and that it was surprising no protective measures appear to have followed it.
Konrad Frysztak, an MP from the ruling Civic Coalition, called for Nawrocki to undergo a medical examination, and other party figures have voiced public scepticism about the account.
The book had not yet been fully published as the debate broke out.
(ał)
Source: tvn24.pl, wp.pl, rmf24.pl, polsatnews.pl