KUALA LUMPUR: Malaysia's anti-corruption agency said Wednesday it will appeal the attorney general's decision to clear Prime Minister Najib Razak of criminal charges over a $681 million financial scandal.

The agency's move disrupts Najib's call to put to rest the scandal that has been the biggest political crisis in his seven-year premiership.

Attorney General Mohamed Apandi Ali said Tuesday that $681 million channeled into Najib's accounts in early 2013, just before national elections, was a personal donation from Saudi Arabia's royal family. He said the donation was without any conditions and that Najib had returned $620 million that was unused.

Based on the anti-corruption agency's investigation, he said he found no criminal wrongdoing and ordered the case closed.

Malaysia's Anti-Corruption Commission, however, said in a statement that it will seek a review of the decision with an independent government panel that among others reviews cases that are not taken to court for prosecution by the public prosecutor.

The agency didn't say if it recommended charges against Najib and gave no other details.

Najib has welcomed the attorney-general's decision, calling the controversy an "unnecessary distraction" for the country amid an economic slowdown. Najib, who has maintained that he didn't use the money for personal gain, indicated that it was for political funding.

Najib has been grappling with deep unhappiness over his leadership, with large street rallies in August calling for his resignation after documents leaked in July suggested that some $700 million was deposited in his private bank accounts from entities linked to indebted state investment fund 1MDB.

He has replaced critics in his government with loyalists, sacked the previous attorney general who had been investigating him, and cracked down on the media.

Opposition lawmakers and many Malaysians are skeptical of Apandi's decision, saying it triggered more questions, such as why Saudi royals would make the donation and whether Najib really returned most of the money.

The attorney general "is taking Malaysians as a nation of fools and simpletons if he expects his bald statements ... to be accepted without any questions," said opposition lawmaker Lim Kit Siang.

Support for Najib's ruling coalition has eroded in the last two general elections. It won in 2013, but lost the popular vote for the first time to an opposition alliance.