Non-Constituency MP Leon Perera of the Workers' Party (WP) said he is no longer an adviser of sociopolitical site The Independent Singapore (TISG), which is being investigated for violating election advertising rules.
He is also in the process of divesting his shareholding in the company that owns and operates the website, he added.
His announcement, posted on his Facebook page yesterday, follows a clarification he made last Thursday about his links with TISG.
Mr Perera had said he was a minority shareholder of the company that owns the website and sat on TISG's advisory board, but was not involved in its management and operations.
On his latest move, he said: "I have decided to take this additional step to ensure that any perceived link to TISG does not distract public attention when policy positions are taken by the WP, particularly on issues related to media regulation."
He added that the move was also necessary as he had been appointed deputy chair of WP's media team.
His statements follow a comment People's Action Party MP Tan Wu Meng made last week about his links to TISG.
Dr Tan, an MP for Jurong GRC, made the point when remarking on the WP's statement about the police probe into online posts made on Cooling-Off Day and Polling Day for the May 7 Bukit Batok by-election.
TISG and two people are being investigated for flouting the rules.
The WP had issued a statement last week, saying it was concerned about the way investigations were reportedly conducted after the two people said online the police had questioned them for long hours, raided their homes and seized their phones and computers.
Dr Tan said given Mr Perera's links to TISG, the WP should make every effort "to avoid the impression that it is trying to interfere with the investigation".
Mr Perera is one of six shareholders of Protegesoft company, which owns the website.
He holds two million of the company's 8.51 million shares, according to official records.
Mr Perera said yesterday he is in the process of divesting his shares to the company's other shareholders.
It should be completed "in the next month or so", he added.
The shareholders are TISG editor and publisher Kumaran Pillai, TISG co-founder and veteran journalist P.N. Balji, publisher of Epigram Books Edmund Wee, lawyer Alfred Dodwell and Ms Sheeba Balakrishnan.