Former prime minister Dr Mahathir Mohamad now believes that the country’s prime ministers should not hold the portfolio of finance minister as well.

This, Mahathir said, is to avoid a repeat of financial scandals such as the one involving 1Malaysia Development Bhd (1MDB).

“Prime ministers should not be the minister of finance,” The Wall Street Journal (WSJ) quoted Mahathir saying at a lecture in London on Wednesday.

“We should put a bar to the prime minister becoming the minister of finance,” he said, acknowledging he himself had also held the finance minister's post for a time during his 22 years as the head of government.

Prime Minister Najib Abdul Razak has held the finance minister's portfolio since September 2008.

The United States Department of Justice in July filed a series of civil lawsuits seeking to seize assets allegedly bought with funds misappropriated from 1MDB.

Najib set up 1MDB, which is now wholly owned by the Finance Ministry, in 2009.

Although the lawsuit did not name Najib, the court documents make numerous references to a figure termed “Malaysian Official 1”, whom a person with direct knowledge of the investigation has confirmed refers to Najib.

Mahathir in his talk also said he supports the actions of the DOJ as well as those in other countries, such as Switzerland, that are investigating 1MDB-linked dealings.

“It is about taking action against people who break the laws of those countries,” he said. “That I think is legitimate.”

In an interview with WSJ, Mahathir said he had met with PKR de facto leader Anwar Ibrahim as part of a plan to create a coalition of opposition politicians capable of ousting Najib in the next general election.

The 1MDB scandal, Mahathir said, was negatively affecting the Malaysian economy by weakening the currency and increasing the national debt burden.

“The solution to the problems in Malaysia is through the removal of the (present) prime minister,” Mahathir said.

“This man has abused his position and has lost billions of dollars.”

Both Najib and 1MDB have denied any wrongdoing.

Najib’s spokesperson, in a statement on Tuesday, defended the prime minister, claiming that Mahathir has, for the past two years, “waged a campaign to unseat a democratically-elected government”.