The Committee on National Security and Defence, which looked into Bastys' ties to Russia's energy sector and Lithuania's underworld, on Wednesday approved the conclusion with six votes in favor.
The committee's conclusions will be put to a vote in the full parliament.
Rosatom is building a nuclear power plant in Belarus, close to the border with Lithuania, and earlier planned to build a nuclear power facility in the Russian exclave of Kaliningrad.
In another conclusion approved by eight members, the committee states that Bastys' close ties to former and current officers of Russian intelligence and security agencies, journalists close to the Kremlin and former and current members of the underworld pose a threat to national security.
The Seimas several weeks ago asked the committee to conduct a parliamentary probe into the lawmaker's ties to Yevgeny Kostin, who is seen as a representative of Rosatom, Piotr Voyeiko, a former KGB agent, Ernest Matskevich, a journalist of the Russian state channel RTR, Saturnas Dubininkas, who is said to be a former Kaunas mafia leader, and Vadim Pakhomov, a businessman suspected of illegal activity.
The panel was also to look into whether Bastys' had acted against the interests of the Lithuanian state by maintaining these contacts and whether the material gathered by the State Security Department provided sufficient grounds for opening impeachment proceedings against the lawmaker.