Former premier Dr Mahathir Mohamad today claimed the three top officials accused of conspiring to topple Prime Minister Najib Abdul Razak were "betrayed".

He said Najib would have faced action if the alleged betrayal did not occur.

"Zeti is upright, so is Abu Kassim and also Gani Patail...but they were betrayed by one among them.

"Otherwise Najib would face action by now," Mahathir told reporters in Kuala Lumpur today.