Paetongtarn Shinawatra, head of Pheu Thai's inclusion and innovation advisory panel, may be investigated for meeting her father, fugitive former premier Thaksin Shinawatra, in Hong Kong recently.
The Election Commission (EC) was asked on Tuesday by Sonthiya Sawasdee, a former adviser to the House committee on law, justice and human rights, to probe Ms Paetongtarn over the Hong Kong meeting.
Mr Sonthiya said the meeting could have breached Section 45 of the organic law on political parties, which forbids party figures from abetting or supporting someone who poses a threat to national peace, order and ethics.
Although declining to say whether Thaksin was such a threat, Mr Sonthiya said the former prime minister has regularly participated in live streaming via the Clubhouse audio-based social networking app to offer his views on a wide range of political issues.
Thaksin, who is widely known to keep close ties with Pheu Thai, fled the country in 2008 prior to being sentenced by the Supreme Court for assisting his former wife in clinching a discounted land deal.
Mr Sonthiya said if Thaksin thought he was innocent in the case, he should have returned to the country to defend himself.
He said that if Thakin is regarded as a threat and Ms Paetongtarn breached Section 45, Pheu Thai would be liable for dissolution and Ms Paetongtarn barred from politics.
Mr Sonthiya said he did not file the petition with the EC against Ms Paetongtarn earlier, despite her having met Thaksin overseas often, because Ms Paetongtarn did not then hold a party position within Pheu Thai.
But now, she holds key posts in the main opposition party. In addition to leading the party's inclusion and innovation advisory panel, she also announced Pheu Thai's election policies, which speaks of her stature in the party, he said. "The blood ties may not be severed. But in terms of the law, there could be consequences," he said.