He denies the allegations.
The Warsaw regional prosecutor’s office said it had launched the checks on Monday on its own initiative.
It is examining possible offences involving coercion and the administration of intoxicating substances.
Kołodziejczak served as deputy agriculture minister until mid-2025.
Before that, he founded and led Agrounia, an agricultural movement that organised protests against government agricultural policy.
He has been an MP since 2023 and belongs to the Civic Coalition’s parliamentary club.
The online outlet Kanał Zero reported on Friday that former female colleagues had accused Kołodziejczak of violent and aggressive behaviour and of pressuring them to take a substance "he claimed was cocaine."
Kołodziejczak described the allegations as slander.
Later that day, Zbigniew Konwiński, head of the KO parliamentary caucus, said Kołodziejczak had been suspended with immediate effect.
He added that the club xpected the relevant authorities to investigate the issue.
On Sunday, Kołodziejczak filed a report with the Internal Security Agency (ABW) in Łódź, central Poland, concerning a suspected offence against him.
He gave no details, saying he wanted the competent authorities, rather than the media, to deal with the matter first.
He said the allegations had hit him hard.
Meanwhile, Justice Minister and Prosecutor General Waldemar Żurek said on X that the era of politically controlled investigations was over.
"Whenever a suspected crime comes to light, prosecutors act on their own initiative," he said, regardless of a person’s name or position, and no one would be treated as untouchable.
(ał)
Source: PAP