The removal of Dr Mahathir Mohamad, his son Mukhriz and three others as Bersatu members had "nothing to do" with the party's disciplinary board, said the board's chief Megat Najmuddin Megat Khas.

When contacted, the veteran politician told Malaysiakini the matter revealed earlier tonight through separate letters signed by Bersatu organising secretary Suhaimi Yahya was an "administrative matter" that was out of the disciplinary board's jurisdiction.

"The letter did not come from me or the disciplinary board [...] it's an administrative matter.

"The issue involves Article 10.2.2 and 10.2.3 which provides for automatic de-registration as members based on their own behaviour and actions," said Megat Najmuddin on the provisions cited as grounds to nullify the five's status as members.

Following news of the removals, Bersatu leaders and members who remain aligned to Mahathir have argued that any move to sack a member must be authorised by the supreme council on advice of the disciplinary board.

Asked whether there was a need to summon the sacked leaders before the disciplinary board, Megat Najmuddin said: "No. The facts speak for themselves [...] what is there for the disciplinary board to look at?"

"Nothing to do with the disciplinary board. It is purely an administrative action to announce that they have automatically disqualified themselves from being a member," he said.

In an immediate response, Mahathir and the four other leaders have rejected the use of the automatic de-registration clause, claiming that it was "unreasonable" and a "shallow" definition.

Megat Najmuddin, however, declined to comment on their joint statement.

Bersatu supreme council member Wan Saiful Wan Jan argued that the party did not sack the five leaders but their move to sit on the opposition bench during the May 18 Dewan Rakyat sitting had led to the automatic nullification of their membership status.

Mahathir had initially declared that he would sit on the opposition bench in Parliament but Penang Bersatu chairperson Marzuki Yahya, who is also the disputed Bersatu secretary-general, later claimed that all five were sitting as independent lawmakers.