KUALA LUMPUR — Malaysian prosecutors have not appealed the acquittal of former Prime Minister Najib Razak in a case of audit tampering related to state fund 1MDB, his lawyers said on Tuesday (Sept 12), risking backlash for Premier Anwar Ibrahim who has vowed to fight graft.

Mr Anwar is already under pressure from allies and the opposition after his government last week dropped dozens of graft charges against a key ally whose support is essential for the premier to keep his parliamentary majority.

Mr Najib, 70, is serving a 12-year jail sentence for another corruption case linked to 1Malaysia Development Berhad (1MDB). He also faces several other graft charges.

The attorney general’s chambers were expected to appeal Mr Najib’s acquittal earlier this year of a charge of abusing his position as prime minister to amend a government audit into 1MDB.

But Mr Najib’s lawyers at Shafee & Co said in a statement, “the prosecution evidently found no grounds for appeal” and did not file the petition.

Mr Najib had pleaded not guilty.

An estimated US$4.5 billion (S$6.1 billion) was allegedly misappropriated from 1MDB by high-level officials of the fund and their associates between 2009 and 2014, the United States Justice Department has alleged.

Mr Anwar, who came to power in November last year, had vowed to fight corruption as part of his election campaign. But concerns were raised after he partnered with Mr Najib’s corruption-tainted party to form a government and appointed officials accused of graft to senior positions.

On Sunday, the Malaysian United Democratic Alliance said it was leaving Mr Anwar’s ruling coalition, citing concerns after graft charges were dropped against Mr Ahmad Zahid Hamidi, the country’s deputy premier.

Mr Anwar has maintained that the move to drop the case, which triggered a widespread public backlash, was made without his interference. REUTERS