KUALA LUMPUR, June 29 — The latest police investigation against Tun Dr Mahathir Mohamad for likening the prime minister to dead Ugandan president Idi Amin is the eighth open case against the former prime minister.

Inspector-General of Police (IGP) Tan Sri Khalid Abu Bakar said the case was being investigated under Section 500 of the Penal Code that pertains to criminal defamation.

"We have been investigating him over a few cases. I think this is the eighth case that we have investigated Tun (for),” Khalid told reporters during a press conference today.

Dr Mahathir Mohamad had his statement taken by the police this morning over the remark he allegedly made while campaigning in the Kuala Kangsar by-election.

Khalid then said it was up to the Attorney-General’s Chambers to decide if Dr Mahathir will be prosecuted.

The late Idi Amin was Uganda’s president for eight years in the 1970s and was most known for leading a violent regime that saw the killing of tens of thousands of people, earning him the moniker "Butcher of Uganda”.

Dr Mahathir had openly campaigned for Pakatan Harapan during the recently concluded by-elections in both Kuala Kangsar and Sungai Besar, claiming the contests would be the people’s referendum on Najib’s leadership.

After Barisan Nasional’s Budiman Mohd Zohdi won the Sungai Besar seat, Prime Minister Datuk Seri Najib Razak made reference to Dr Mahathir’s comment comparing him to Amin.

"He said I am the Idi Amin of Malaysia. Well, the Idi Amin of Malaysia is more popular,” Najib said on June 19 at the Sungai Besar Umno headquarters.

Dr Mahathir is currently under several police investigations, including one over his recent claim that the Malay rulers may be under house arrest.