The Malaysian Anti-Corruption Commission (MACC) has obtained an explanation from the source of the RM2.6 billion donation deposited into Prime Minister Najib Abdul Razak's personal bank accounts.

However, the commission said it cannot reveal the identity of the donor, whom it said was from the Middle East.

"MACC obtained details of the donor from bank documents and found there were four letters submitted to the bank when the large sum of money was deposited into the prime minister's accounts.

"In the documents, it was stated that the RM2.6 billion was donation," read the statement.

The commission said it would now question the prime minister to get his side of the story.

The statement was not signed by any official. MACC chief Abu Kassim Mohamed is currently on leave while his deputy Mohd Shukri Abdull is abroad.

MACC's statement today corroborated a leaked video in which former deputy prime minister Muhyiddin Yassin said Najib had admitted to receiving RM2.6 billion from a Middle Eastern source.

So far Najib has not denied receiving the money, only saying that he had never used it for personal gain.

The commission said its statement today followed advice from attorney-general Muhamad Apandi Ali that it should clear the air that it had not stopped probing the RM2.6 billion deposited into Najib's accounts.

"MACC would like to stress it never said the case was closed. MACC has only said that the money was not from 1MDB," it said.

The commission also assured that its investigation would be done without fear or favour, and that MACC would not allow anyone to influence the probe.