The case that has gripped the nation and attracted significant international media attention finally concluded last Tuesday with attorney-general Mohamed Apandi Ali clearing Prime Minister Najib Abdul Razak of any wrongdoing.

The prime minister may have been cleared by the country’s top prosecutor, but his critics remain doubtful and the attorney-general’s decision has been ridiculed by various quarters.

However, Najib’s detractors would be less than happy to note that not even the highest court in Malaysia can overturn the AG’s decision to clear him of any wrongdoing, a source close to the Prime Minister’s Department told British daily The Guardian .

The decision to clear Najib would be constitutionally “impossible” to overturn, said the source, who requested anonymity.

“Not even the highest court in Malaysia can. The constitution would have to be changed, and that’s not going to happen," the source is quoted as saying.

Citing the investigations carried out by the Malaysian Anti-Corruption Commission (MACC) into the RM2.6 billion political donation and RM42 million from SRC International transferred into Najib's personal bank accounts, Apandi on Tuesday declared that the prime minister had committed no criminal offence .

'Najib returned RM2.03 billion'

Apandi also disclosed that Najib had returned RM2.03 billion to the Saudi royal family, two months after the 13th general elections in May 2013.

However, sources from the MACC have said that Apandi had ignored the commission’s recommendation to charge Najib with criminal misappropriation.

Najib, on the other hand, has time and again denied any wrongdoing on his part, and on Tuesday, after Apandi’s announcement, said it was time for Malaysia to " move on ".

The prime minister also said that the attorney-general’s findings affirmed his repeated assertions that "no crime was committed".

The money transfers were first disclosed by The Wall Street Journal and whistleblower website Sarawak Report last July 3, based on documents leaked from Malaysian investigators.

Twenty-five days later, Apandi's predecessor Abdul Gani Patail was removed on health grounds, sparking off speculation his removal could be related to the investigations into the money transfers.