KUALA LUMPUR, July 14 — As Tun Dr Mahathir Mohamad ramps up his attacks against Prime Minister Datuk Seri Najib Razak, a Malay group demanded today the former leader come clean on the wealth source of his two sons Mirzan and Tan Sri Mokhzani.

At a news conference here, Jaringan Melayu Malaysia (JMM) alleged the two sons of Malaysia’s fourth and longest-serving prime minister had become rich from financial misappropriation during Dr Mahathir’s 22-year administration.

To back its claim, JMM held up a list of supercars allegedly owned by multi-billionaire Mokhzani worth RM36.2 million in total, including one McLaren P1 said to be worth RM6.2 million.

“It is unfair for somebody who tries to reproach others, but he also has his own weakness,” JMM president Azwanddin Hamzah told reporters, referring to Dr Mahathir.

Azwanddin said it is “suspicious” that Mirzan and Mokhzani could have accumulated such billions of ringgit in wealth in such a "short time”, although he failed to elaborate on the timeline of the duo’s wealth growth.

He repeatedly gave Malaysia International Shipping Corporation Bhd’s buy of Konsortium Perkapalan Bhd in 1998 as an example of how a bailout during Dr Mahathir’s time had benefited Mokhzani, although the latter was owned by Mirzan.

JMM also did not explain the source for its list of supercars and how they were linked to Mokhzani, although it did provide a list of corresponding registration plate numbers.

“The authorities do not need to ask for any evidence or testimony, because this issue is always in the media, same as the case of Wall Street Journal,” JMM said in an accompanying statement, as it urge the Malaysian Anti-Corruption Commission and the police to start its investigation on Dr Mahathir’s children.

In the past few months, Dr Mahathir has been calling for Najib to resign, citing the latter’s handling of allegations surrounding 1Malaysia Development Bhd, the state-owned investment firm that has amassed a debt pile worth over RM42 billion in just a few years.