Malaysia's anti-corruption chief, who had been investigating scandal-hit state fund 1MDB, said Friday she had resigned after a reformist government collapsed and a graft-tainted party took power.

The "Pact of Hope" alliance, which stormed to a historic victory in 2018 and ousted a long-ruling coalition, fell apart amid infighting last week and prime minister Mahathir Mohamad resigned.

Mahathir, 94, then sought to return as premier but unexpectedly lost to ex-interior minister Muhyiddin Yassin, who heads a coalition dominated by the multi-ethnic country's Malay Muslim majority.

Latheefa Koya, a leading human rights activist who had been head of the anti-corruption commission since June, said she had informed Muhyiddin she was quitting earlier this week but insisted she was not pressured.

"I also briefed the prime minister about our ongoing actions and efforts for the recovery of the stolen 1MDB monies from abroad," she said in a statement.

Billions were stolen from 1MDB and spent on everything from a super-yacht to artworks, in a fraud allegedly involving ex-premier Najib Razak and his cronies
Billions were stolen from 1MDB and spent on everything from a super-yacht to artworks, in a fraud allegedly involving ex-premier Najib Razak and his cronies AFP / MANAN VATSYAYANA

"He was fully supportive of these actions."

Last week, Malaysia's attorney general Tommy Thomas, who had brought corruption charges against ex-premier Najib Razak over the 1MDB controversy, also resigned.

Billions of dollars were stolen from 1Malaysia Development Berhad and spent on everything from a super-yacht to pricey artworks, in a fraud allegedly involving Najib and his cronies.

Najib's coalition, which had governed Malaysia for six decades, was ejected from power in 2018 in large part due to the 1MDB allegations, and he is on trial for corruption.

Mahathir's government had started recovering money from overseas allegedly looted from the fund.

But the new ruling coalition includes Najib's United Malays National Organisation (UMNO) party, and there are concerns his trial and others linked to the 1MDB scandal could be affected.