Mr Lin Zhong, a 20-year-old who worked in a furnishings factory, was said to be with three colleagues in chest-deep water just off the shore when he went under.

It is unclear how much time elapsed before another co-worker discovered that Mr Lin, who could not swim, had disappeared. No one heard any cries for help.

The colleague, Mr Ang Lian Kwee, 64, said he was swimming towards the shore when he saw a head bobbing in the water. Soon after, it disappeared.

He raised the alarm, sparking a search mission by police boats, amphibious vehicles and rescue divers. The body was recovered six hours later after being spotted by a beach-goer just before nightfall.

Mr Ang told The Straits Times that he had taken the group of four Chinese workers to the beach - their first time there - yesterday around noon.

They stripped down to their swimming shorts and played in the water about 2m from the shore, while Mr Ang swam out farther.

At about 1pm, Mr Ang was about 35m out and facing the beach when he saw a head of black hair drifting away.

He jerked his head towards the group and realised there were only three men - who were taking photos - near the shore.

He quickly swam towards Mr Lin, but his head vanished when he was 3m or 4m away. 'I swam there and groped and kicked everywhere but I couldn't feel him anywhere in the water,' he said in Mandarin. Mr Ang screamed at his colleagues and beach-goers for help.

Read the full story in Monday's edition of The Straits Times.