Thailand’s Election Commission will investigate if prime minister frontrunner Pita Limjaroenrat violated an election rule on candidacy after earlier throwing out some complaints against him, according to local media reports.

The six-member election panel’s decision to launch its own probe came after its unanimous vote on Friday to throw out three complaints previously lodged against Pita, the Bangkok Post reported, citing a person it didn’t identify.

A representative for the office of the Election Commission told Bloomberg News he couldn’t confirm reports of the probe.

Complaints had been lodged against Pita that alleged he was holding shares in a media company, urging the election body to seek a Constitutional Court ruling if he should be disqualified as a member of parliament and prime minister candidate under the charter.

The Election Commission will probe if Pita had applied to contest in the May 14 general election despite knowing he was not eligible, which would breach Section 151 of Thailand’s election law, according to local media. Applicants are forbidden from holding shares in a media company under Thai laws.

The penalty for breaching the law is as long as 10 years in prison and a ban from politics for 20 years. Criminal procedures usually involve many steps and can take months or years, and Pita could be confirmed as a member of parliament in the meantime when the Election Commission certifies election results by the July 13 deadline.

The investigation is the latest hurdle for a coalition of pro-democracy parties in their attempt to take power after sweeping the May election. Pita’s bloc is seeking the backing of enough lawmakers to ensure his selection as premier in a joint sitting of the lower and upper houses of parliament, prompting jittery investors to dump Thai stocks, bonds and the currency.

The original share ownership petition by political activist Ruangkrai Leekitwattana sought Pita’s disqualification for his alleged ownership of 42,000 shares in long-defunct ITV Pcl.

The leader of the Move Forward Party denied the allegations this week, saying that the firm didn’t operate in media since 2007 and he didn’t own the shares but only managed them as part of an estate left behind by his late father. He said he had transferred the shares to avoid the company being “revived” as a media firm to disqualify him later.

Thai PM Frontrunner Pita Unfazed by Media Share Controversy

Pita’s path to the premiership is rocky, with the Election Commission probe and shareholding complaints that could be refiled after he takes office as a lawmaker, said Somchai Srisutthiyakorn, an academic and former election commissioner.

“If the Election Commission files a criminal complaint and even if it’s still in process, that is enough excuse for the senators who are opposed to voting for Pita as prime minister to insist on not doing so,” said Somchai. “The weapons of war are being brought out to the battlefield.”