Yap Wai Keat, who heads AmBank’s capital market desk, said it was also sensitive because of the large amounts of money being remitted in and out of his account in US dollars.

“It was a sensitive account as he was the prime minister at the time. As the account belonged to Najib, who is a PEP, we had to handle it carefully,” the 38th prosecution witness said when cross-examined by lawyer Wan Aizuddin Wan Mohammed.

Najib was also finance minister from 2009 to 2018.

The lawyer had asked Yap about the inflow and outflow of money in US dollars and why he considered the account to be sensitive.

The transactions were handled under a current account ending with the digits 9694 but Yap said he knew who the owner was from AmBank relationship manager Joanna Yu.

“Yu had told us who was the beneficiary of the money that was coming in,” said Yap whose task was to convert money received in US dollars into ringgit.

He said the local currency market would have reacted due to US$680 million (RM2.08 billion) coming in in March and April 2013 and US$620 million (RM2.03 billion) going out in August 2013.

Wan Aizuddin noted that a US$10 million transaction would not cause a ripple effect on the market but US$600 million-plus would certainly have.

Najib, 69, is facing four charges of using his position to obtain bribes totalling RM2.3 billion from 1MDB funds and 21 charges of money laundering involving the same amount.

The prosecution contends that the money belonged to the state investor who had taken loans and issued bonds to undertake local and overseas infrastructure projects with good returns.

However, the defence has taken the position that the money was a donation to Najib from the Arab royal family.

The hearing before judge Collin Lawrence Sequerah has been adjourned to Monday.