The four men appeared in the District Court on Monday over Second Sergeant Hu Enhuai's death in August last year during a combat survival course at Pulau Tekong, an islet reserved for military use, the Straits Times said.

According to the charges, Hu's head was repeatedly submerged into a tub of water for up to 20 seconds each time.

The four, who have been suspended from their duties, also stand accused for inflicting "near drowning with acute respiratory distress syndrome" on another serviceman, 26-year-old Captain Ho Wan Huo, through the same training methods.

Captain Pandiaraj Mayandi, the supervising officer of the Combat Survival Training Course, has been charged with ordering the drill, the Straits Times reported.

Course commander S. Balakrishnan is accused of not stopping the exercise, with Lieutenants Ng Chin Fong and Divanandhari Ambat Chandrasekharan charged for carrying out the dunking, the paper said.

A pre-trial conference will be held on June 22, with all four men facing a maximum two years' jail, according to the daily.

Defence Minister Teo Chee Hean said in parliament last year the incident was "a stain on the reputation" of the Singapore Armed Forces.

All able-bodied Singaporean men are required to undergo two-and-a-half years of military training from the age of 18, after which they have to attend annual refresher courses.

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