Janusz Kowalski made the statement on the X social media platform on Wednesday night, state broadcaster TVP Info reported.
The MP shared what he said were government documents from 2009 showing that Polish and Russian authorities had been planning to build "electricity links" between Poland and Russia's neighbouring exclave of Kaliningrad.
Poland was set to buy power from the Baltic Nuclear Plant, which Russia planned to build in Kaliningrad, TVP Info reported.
The documents also show that the Polish government at the time lobbied for Russia's accession to the World Trade Organisation, according to Kowalski, who was until recently a member of a state panel tasked with investigating Russian interference in Poland's internal security from 2007 to 2022.
Earlier in the day, Kowalski's state commission into Russian influence unveiled a progress report from its work so far, Polish state news agency PAP reported.
The panel said that Poland's Military Counterintelligence Service (SKW) had maintained close contacts with Russia's Federal Security Service FSB between 2010 and 2014, without the formal consent of the prime minister at the time.
The commission's head, Sławomir Cenckiewicz, had earlier told the media that the cooperation "had not been consulted with NATO allies."
He added that some Western countries "protested against these links," as did Poland's internal security agency ABW.
In its progress report, the commission recommended that Tusk and senior ministers in his Cabinet at the time "should not be appointed to positions with responsibility for national security."
Tusk, a former top European Union official and Poland's current opposition leader, who is likely to be elected the country's next head of government, said the creation of the panel had been "politically motivated" and the commission's report "proves this," the PAP news agency reported.
On Wednesday night, Polish lawmakers voted to dismiss the members of the commission into Russian influence, including Kowalski.
The move was backed by MPs from Tusk's liberal Civic Coalition (KO), the rural-based Polish People's Party (PSL), the centre-right Poland 2050 group, the Left party, and some lawmakers with the far-right Confederation group, news outlets reported.
The commission had been appointed by the previous parliament, controlled by the ruling conservative Law and Justice (PiS) party.
(pm/gs)
Source: TVP Info, PAP