If the Malaysian Anti-Corruption Commission (MACC) can rule out that RM2.67 billion deposited into Prime Minister Najib Abdul Razak's private bank accounts did not come from 1MDB, then it would only be natural to assume that it is aware of the exact source of the funds.

As such, Pokok Sena MP Mahfuz Omar said the MACC owes it to the public to release this information.

"If the MACC in its investigation found that the RM2.67 billion in the prime minister's personal accounts is not from 1MDB, it is impossible that the MACC does not know who the generous donor is.

"Did the MACC investigation also find out what was the purpose of the donor in donating directly into Najib's bank account?

"Did MACC establish if the donor received anything in return for the donation?" he said in a statement today.

Likewise he questioned whether Bank Negara was alerted to the transaction as it exceeded the RM50,000 threshold that would require the central bank to be informed.

Yesterday, the MACC declared that the massive funds received by Najib was not from 1MDB but were "donations".

However, it did not reveal where the money came from.

Meanwhile, PAS' Temerloh MP Nasruddin Hassan condemned the police's move to arrest the MACC officer investigating the deposit into Najib's account.

"It shows a planned action to cover up the 1MDB financial scandal when one by one those who were involved in the scandal's expose have been 'sacrificed'," he alleged in a statement.

Yesterday, MACC special operations director Bahri Mohamad Zin speculated "hidden hands" were behind the police's move to arrest his investigators, adding that the cops would not willingly do such "mad work".