SINGAPORE - Days after a blast at the Tuas workshop killed three workers in February, the project engineer of the company deleted messages and a picture of the damaged machine from both his mobile phone and one of his dead colleague's.

Mr Lwin Moe Tun, 31, who is employed by Stars Engrg, was the fifth worker to testify on Wednesday (Sept 29) before an inquiry committee looking into the cause and circumstances of the blast.

Seven workers were injured, and three workers were killed in the Feb 24 blast at the Stars Engrg workshop at 32E Tuas Avenue 11.

Mr Subbaiyan Marimuthu, 38, Mr Anisuzzaman Md, 29, and Mr Shohel Md, 23, died from severe burns that covered 90 per cent of their bodies.

Mr Lwin Moe Tun was not in the workshop when the explosion occurred.

On Wednesday, the Myanmar national said Mr Marimuthu had sent him a photo at 11.13am, minutes before the blast.

It showed a damaged heater still on the mixer machine with green taping around the heater's wiring.

The first deleted message that Mr Lwin Moe Tun sent was at 11.32am and read: "Ok let me know ASAP".

He said he sent this to Mr Marimuthu as he thought that the worker was going to check the damaged heater.

The second message, sent by Mr Lwin Moe Tun to Mr Marimuthu at 12.09pm, contained an expletive.

Stars Engrg made an insulation material called fire wrap using the mixer machine. The inquiry committee, chaired by Senior District Judge Ong Hian Sun, had earlier heard that the blast could have been linked to that machine.

The machine heated up oil in a jacket, which then heated ingredients, including potato starch, in the mixer component.

It had caught fire earlier in the morning of Feb 24, which prompted Mr Marimuthu to alert Mr Lwin Moe Tun to the damaged heater.

Mr Lwin Moe Tun testified that he had Mr Marimuthu's phone because it was handed to him at the Tuas site by an officer after the blast. It was not specified where the officer was from.

He added that he turned on the phone on Feb 26, hoping to find Mr Marimuthu's brother's contact number because another worker had said he wanted to contact him.

"I then came across the messages and photos that I had already deleted from my phone," said Mr Lwin Moe Tun.

He added that Mr Chua Xing Da, Stars Engrg's sole director, gave him permission to delete the messages from his own phone.

He had asked Mr Chua if he could delete the messages from Mr Marimuthu's phone but Mr Chua had not agreed.

He said that he did not initially mention deleting the messages and the picture to the Ministry of Manpower officers as he was trying to recover them using software he bought.

"In the end, I was unable to retrieve them. I only told the MOM investigators that I had made the above deletions during my second interview with them on 13 April 2021," he said.

Earlier on Wednesday, the inquiry committee heard the testimonies of four workers injured in the blast.

Two were Stars Engrg employees working in the workshop at the time of the blast, while the other two work for another company and were in a neighbouring unit.

The hearing continues on Thursday, with Mr Lwin Moe Tun being cross-examined.