Workers' Party (WP) Non-Constituency MP Leon Perera said he is not involved in the management and operations of socio-political site The Independent Singapore (TISG), which is being investigated for violations of election advertising rules.
Mr Perera also said yesterday that he is not a member of the website's board of directors.
He is, however, a minority shareholder whose role, he said, is limited to "providing occasional advice on long-term business strategy, not on editorial decisions or content".
His statement, which he posted on his Facebook page, comes a day after People's Action Party MP Tan Wu Meng made a comment about Mr Perera's links to TISG.
Dr Tan, an MP for Jurong GRC, made the point in a Facebook post, when remarking on the WP's statement about the police probe into online posts on May 6 and May 7, Cooling-Off Day and Polling Day for the Bukit Batok by-election.
The WP had said it was concerned about the way investigations were reportedly conducted, and urged the authorities to ensure consistency and proportionality in probes.
Dr Tan, who said the law should be allowed to run its course, said that given Mr Perera's links to TISG, the WP "could be seen as having an interest in the outcome of the investigation". He added that the party should make every effort "to avoid the impression that it is trying to interfere with the investigation".
Mr Perera, in his response, said his involvement in the website was "a matter of public record" and that he had declared it in a previous interview with the news site Mothership.
He is one of six shareholders of Protegesoft company, which owns TISG. He owns two million of the company's 8.51 million shares, according to official records. He is also a member of TISG's advisory board.
Blogger Roy Ngerng and former political detainee Teo Soh Lung are also being investigated for online posts made on May 6 in contravention of election advertising rules.
The duo have said they were interrogated for long hours by the police on Tuesday and that their homes were "raided". They added that their phones and computers were confiscated.
A group of 141 activists and members of the public said yesterday in a statement that they were "gravely concerned" by the seizure of the duo's belongings without a warrant, and the archiving of their personal data. These actions are "completely disproportionate to any harm alleged to have been caused by the actions of Mr Ngerng and Ms Teo", the statement said.