SINGAPORE - The last words uttered by Corporal Kok Yuen Chin before falling into the 12m-deep pump well were of protest.

"Cannot encik," the 22-year-old had said, using the Malay word for "mister", just seconds before he was pushed into the Tuas View Fire Station pump well where he drowned during a ragging incident to mark the completion of his national service.

Regular specialists in the Singapore Civil Defence Force (SCDF) are referred to as encik.

Cpl Kok's last words were heard in video footage shown in court on Monday (June 17) during an ongoing trial.

The officers in charge of the fire station on May 13 last year, the day of the ragging incident, are contesting the charges.

The two on trial - Kenneth Chong Chee Boon, 38, a lieutenant, and Nazhan Mohamed Nazi, 40, a first senior warrant officer - were rota commander and deputy rota commander, respectively, that night.

The commanders were each charged in July last year with aiding a rash act that caused grievous hurt by illegal omission.

They had allegedly failed to prevent a group of officers from making Cpl Kok enter the pump well, thereby endangering his life.

Three more officers were charged for their involvement, of which two - including Staff Sergeant Adighazali Suhaimi - have been convicted.

Last December, Staff Sgt Adighazali was sentenced to a month's jail.

He had pleaded guilty to intentionally obstructing the course of justice by deleting video footage that showed Cpl Kok sitting at the edge of the well before he was pushed in.

He has finished serving his sentence and took the stand on Monday on the sixth day of the trial.

The night of May 13 last year started out with a cake-cutting ceremony for Cpl Kok, a Malaysian national and Singapore permanent resident.

During the ceremony, there were mentions of the pump well, which the men refer to as "kolam".

In video evidence of the events leading to the full-time national serviceman's death, various people could be heard teasing him about the kolam ritual, which involved Cpl Kok getting into the pump well.

Staff Sgt Adighazali, 33, said he had given Cpl Kok advice about the kolam ritual.

"I told him personally, one-to-one, either you go in by yourself or somebody will push you," said Staff Sgt Adighazali.

When the prosecution asked why he had said this, Staff Sgt Adighazali said it was "just advice" to Cpl Kok. Probed further about the reason for such advice, he said he believed that there was less chance of injury if a person entered the pump well himself, compared to being pushed.

He also said he thought that someone would push Cpl Kok into the well if he did not enter himself, as there was "persistent cheering to want to see him go in".

Staff Sgt Adighazali also gave his account of what happened that night.

He said the mention of kolam and the act of carrying Cpl Kok towards the pump well was "just joking and teasing" until a commotion happened while the group was gathered at the well.

He said he thought the "prank" would stop after they had put Cpl Kok on the ground near the well. "But there was a commotion, and that was when I felt that something was going to happen."

At some point, someone told the men to stop the activity and he was told to quit taking video, but the commotion built up and soon after, Cpl Kok was pushed into the well.

The trial will continue later in the day, when Staff Sgt Adighazali is expected to be cross-examined by lawyers for Chong and Nazhan.