A spokesperson for the Saudi Foreign Ministry said it is looking into the claim that Prime Minister Najib Abdul Razak received a political donation amounting to RM2.6 billion.

According to a report in the Wall Street Journal , the spokesperson said no comments would be provided at the moment.

The donation was said to be made under the kingdom's previous monarch, King Abdullah, who died a year ago.

Last July, WSJ and whistleblower Sarawak Report had exposed the donation issue based on leaked documents from Malaysian investigators.

Najib also threatened to sue WSJ, but has yet to do so.

As for Sarawak Report , the government has blocked access to the website and accused its London-based editor Claire Rewcastle-Brown of being part of a plot to topple the prime minister.

This morning, attorney-general Mohamed Apandi Ali said there was no grounds to file charges against the prime minister in relation to this case.

He said Najib had also returned RM2.03 billion to the Saudi royal family in 2013.

Apandi said he was satisfied based on evidence from witnesses and supporting documents submitted by the Malaysian Anti-Corruption Commission (MACC) that the original sum transferred between March 22 and April 10, 2013 was a "personal donation from the Saudi royal family given to him (Najib) without any consideration".

"MACC in their investigation, personally met and recorded statements from witnesses including the donor which confirmed the donation was given to PM personally," he added.

"I am satisfied there is no evidence to show there was a form of gratification given corruptly.

"Evidence obtained from the investigation does not show the donation was given as an inducement or reward for doing or forbearing to do anything in relation to his capacity as prime minister," he told a press conference in Putrajaya.

Najib has repeatedly denied having committed any wrongdoing.