A by-election in Negeri Sembilan state could become a crowded six-way contest, after a former aide to politician Anwar Ibrahim - who had accused him of sodomy - said yesterday that he, too, would stand as a candidate.

Mr Mohd Saiful Bukhari Azlan said he planned to stand as an independent in the Port Dickson vote.

Mr Saiful would join at least four others who had announced their wish to contest in the Oct 13 by-election against Datuk Seri Anwar.

They are controversial former Umno leader Isa Samad, former air force officer Mohd Nazari Mokhtar from Parti Islam SeMalaysia, independent candidate Stevie Chan Keng Leong and Parti Rakyat Malaysia member Ahmad Kamaruddin.

Nomination for the contest will be held today. The by-election is being called after the Port Dickson MP controversially stepped down to allow Mr Anwar, Parti Keadilan Rakyat's president-elect, to contest the seat and return to Parliament.

Umno is boycotting the contest, saying the ward was vacated to "fulfil the political ambitions of one person".

In June 2008, Mr Saiful lodged a police report claiming that he had been sodomised by Mr Anwar at a condominium in Kuala Lumpur. The case was taken to the courts. In February 2015, the apex Federal Court upheld Mr Anwar's conviction and a three-year jail term for sodomising Mr Saiful in June 2008. Mr Anwar left jail in May this year after the Pakatan Harapan alliance won the general election, and he was given a full pardon by the King on May 16.

Mr Saiful told The Star newspaper yesterday: "I am contesting purely as an independent without any party backing me. Let me set the record straight, I am not contesting because of my past with Datuk Seri Anwar but for other reasons." But he added that he would only reveal what these were once his nomination as a candidate is confirmed.