WARSAW, Jan 30 (Reuters) - Polish prosecutors will investigate state-controlled oil company Orlen's takeover of smaller peer Lotos, acting on a complaint made in 2022, a member of parliament for the new coalition government said on Tuesday.

The company sold some of Lotos' assets to buyers including Saudi Aramco and Hungary's MOL to meet EU antitrust rulings, but opposition politicians at the time said they were sold at too low a price.

Agnieszka Pomaska, a lawmaker in the pro-European coalition government that took power last month, said she had informed prosecutors that a crime may have been committed in December 2022, but only received a response last week.

"The prosecutor's office investigation will concern contracts related to both the merger of Lotos and Orlen, but will also concern the sale of Lotos," Pomaska told reporters.

"The prosecutor's office says directly that significant financial damage could have been caused to Orlen, no less than 4 billion zlotys ($994 million)."

There was no suggestion of wrongdoing on the part of the buyers of the assets.

In an emailed comment, Orlen said the merger was a transparent process, "supervised and controlled by a number of institutions".

"All merger transactions were carried out in accordance with provisions of law and under the supervision of Polish and European authorities," it added.

Pomaska said prosecutors would also investigate the head of the country's antitrust watchdog who approved the asset sales, adding that the sale of Lotos's assets had damaged Poland's energy security.

The watchdog, UOKiK, did not immediately respond to an emailed request for comment.

She said that if company board members were found guilty, they could face anywhere between 3 months and 10 years in prison.

Since coming to power in December the new government has set about undoing reforms to Poland's judicial system that critics said had politicised it, and holding those connected to the former nationalist Law and Justice (PiS) administration it accuses of wrongdoing to account.

Critics say that during PiS's time in office the public prosecution service had become politicised, with those willing to follow the government's wishes advancing quickly in their careers and those who did not fearing punishment. PiS has rejected the criticism.

Pomaska said the accusations against Orlen were "very serious". "I have no doubt that today the prosecutor's office may feel that no politicians, neither the ruling party nor the opposition party, will pressure them," she added.

($1 = 4.0240 zlotys) (Reporting by Alan Charlish and Anna Wlodarczak-Semczuk; Editing by Jan Harvey)