The former prime minister said his recent comments which have led to a police investigation were merely about the Malay rulers of old, and not the current royal institution.

“This is common knowledge, can’t I talk about it?” he said, according to Harian Metro.

Last week, police recorded Mahathir’s statement for allegedly insulting the royal institution.

Malaysiakini reported that the probe was related to a video in which Mahathir was alleged to have said the Malays could not depend on the Malay rulers to “protect” them.

The former Umno president had reportedly said the Malay rulers handed over their states to the British to remain in power.

Mahathir is being investigated under Section 124B of the Penal Code for “committing an activity detrimental to parliamentary democracy”, which carries a punishment of up to 20 years in jail upon conviction.

He is also being investigated over the Malay Proclamation.