An audit officer secretly recorded a meeting in 2016 where former prime minister Najib Razak allegedly discussed removing several key sections from the 1Malaysia Development Berhad's (1MDB) audit report that was to be presented to a parliamentary committee.

The 2hr 45min recording made by National Audit Department officer Nor Salwani Muhammad of a meeting on Feb 24, 2016, held by top officials from the government and 1MDB, was tendered as evidence in the High Court yesterday in the trial of Najib, who allegedly asked for the report to remove four contentious issues, including the presence of fugitive businessman Low Taek Jho, better known as Jho Low, in one 1MDB meeting.

Despite not being allowed inside, the 52-year-old witness said she had hidden a voice recorder in the stationery case of another officer who attended the meeting.

"I should have been present because this was regarding our audit, because I was the coordinator. So, I should have taken the minutes," she testified yesterday.

The court was also told that the meeting was chaired by the former chief secretary to the government Ali Hamsa and attended by then Auditor-General Ambrin Buang, former chief private secretary to the prime minister Shukry Salleh, ex-1MDB chief executive Arul Kanda Kandasamy and Attorney-General's Chambers officer Dzulkifli Ahmad.

Ms Salwani told the court that she also secretly kept one of 60 copies of the original report, which the department had prepared in 2016, before it was allegedly tampered with.

Her then boss Tan Sri Ambrin had ordered that all the original copies be destroyed to prevent leaks, while the modified version was submitted to the parliamentary committee.

"I kept the report to be given to the new auditor-general. With pure intention, I had surrendered the report watermarked '09' to allow the new auditor-general to get the whole picture about the audit findings," she said.

The evidence saved by Ms Salwani could become a crucial platform for the prosecution.

The authenticity of the recording was confirmed by Tan Sri Ali on Wednesday, when he was called to take the stand to identify several voices.

On Tuesday, Mr Ali also testified that the meeting was called following Najib's instructions to remove "dissatisfactory content" in the report.

This trial is Najib's third involving 1MDB. He has been charged with using his position to order amendments to the 1MDB final audit report to avoid any disciplinary action against him, while Arul Kanda was charged with abetting Najib.