"The water was murky and muddy, so I could not see clearly but used my hands to touch and feel," he said. "I found one first, a body so small that just one hand was all it took to pull it up.

"It was much crueller when we saw them ashore - with the kids' heads covered by plastic bags and tape, their hands tied up and crossed over their chests, and their legs also tightly bound," the 37-year-old, now the father of a 2-year-old daughter, said in a firm but calm voice.

"The murder scene leapt to my mind the moment I saw the poor kids. It shocked people on the spot and made most feel uncomfortable, including the police."

He said he left the crowd quietly after finishing his duty.

"It's different from searching for other criminal evidence, for example, a murder weapon," he said.

"Recovering human bodies underwater brings higher pressure. It is also the most unhappy and challenging part, which means many skillful divers are not cut out for the job."