The calls come after the parliament's Committee on National Security and Defense (NSGK) completed on Wednesday its probe into business and interest groups' influence on political processes and decision-makers.
Prime Minister Saulius Skvernelis, who was appointed to his post by LVŽS, says that further investigations should disclose the circumstances surrounding possibly non-transparent funding of political parties.
"If the circumstances of allegedly non-transparent funding of political parties in different periods remain undisclosed, then these investigations need to continue," he told reporters.
"Apparently, it would be the Seimas and other bodies," the prime minister said when asked who could carry out all these investigations.
LVŽS Chairman Ramūnas Karbauskis also called for a further parliamentary investigation.
According to him, the findings of the NSGK's recent probe give the impression that businesses exerted unlawful influence on politicians, but fail to disclose the responsibility of politicians themselves.