Saudi Arabia Foreign Minister Adel Al-Jubeir has been reported saying he does not think the RM2.6 billion deposited into Prime Minister Najib Abdul Razak personal bank accounts was a political donation, or that it originated from the Saudi government.

Instead, the minister said the money was from an unspecified "investment".

"It is (from) a private Saudi citizen, I believe, and the funds went to an investment in Malaysia," Al-Jubeir was quoted as saying in a report by The New York Times yesterday.

However, Al-Jubeir said he accepted the Malaysian attorney-general's opinion that there was no wrongdoing committed.

The report also quoted two separate unnamed sources who confirmed that the money was not a donation.

They claimed the money was, in fact, part of a "business deal".

"One member of the royal family and one associate of the family - speaking on the condition of anonymity - said that the money had come from a Saudi prince and confirmed that it was not a donation.

"The associate questioned the reported sum, but said the funds were part of a business deal," noted the report.

The RM2.6 billion funds in Najib's personal bank accounts was first revealed in a Wall Street Journal report July last year, which cited leaked investigation papers.

Najib later claimed that the money was a political donation from the Middle East.

The Malaysian Anti-Corruption Commission (MACC) also concurred that the RM2.6 billion was a "donation" but pursued an investigation, together with a separate deposit of RM42 million into the premier's accounts from state-owned SRC International.

MACC was reported to have submitted its investigation papers to attorney-general Mohamed Apandi Ali last December, which he subsequently rejected.

Apandi had also instructed the MACC to drop the case, saying he was "satisfied that no criminal offence has been committed by the prime minister". The commission, however, decided to appeal the decision.

This is amid Swiss authorities claiming that its investigation into 1MDB-linked entities revealed that US$4 billion had been misappropriated from Malaysian state companies.

In the meantime, Singapore has frozen several bank accounts linked to 1MDB over suspected money laundering offences, while Hong Kong also has an ongoing investigation.