The High Court yesterday struck out a lawsuit brought against the Singapore Armed Forces (SAF) by the family of a full-time national serviceman who died in 2012 after an allergic reaction to smoke grenades during a military exercise.

The family of Private Dominique Sarron Lee had also sued his platoon commander and the chief safety officer of the exercise, alleging negligence on their part.

All three defendants applied to strike out the lawsuit, which was filed last year.

They relied on a provision in the Government Proceedings Act, arguing that it grants them immunity from being sued for negligence.

Under the Act, a member of the armed forces who causes the death of another while on duty cannot be held liable for a civil wrongdoing. Neither can the Government.

Mr R. S. Bajwa, who acted for platoon commander Captain Najib Hanuk Muhammad Jalal, and Mr Laurence Goh, who acted for safety officer Captain Chia Thye Siong, argued that their clients were protected as they were carrying out duties as members of the SAF.

Mr Irving Choh, acting for the family, argued that immunity did not apply as their actions fell outside the scope of their duties; Capt Najib detonated six smoke grenades when safety regulations specified two.

Mr Choh also argued that there was a contract between SAF and Pte Lee, and his family is entitled to damages as SAF had breached its contractual duty to ensure the highest standards of training safety.

But the SAF, represented by the Attorney-General's Chambers, argued that the legal relationship between SAF and Pte Lee was not contractual.

Yesterday, in a chambers hearing, Judicial Commissioner Kannan Ramesh found the Act applied in Pte Lee's case. He also rejected Mr Choh's argument that SAF and Pte Lee had a contractual relationship.

Pte Lee's family has to pay costs of $22,000 to the three defendants.

On April 17, 2012, Pte Lee suffered breathing difficulties and passed out during an exercise in Lim Chu Kang.

The 21-year-old, who was asthmatic, was evacuated to Sungei Gedong Medical Centre before being hospitalised at National University Hospital, where he was pronounced dead at about 2pm the same day.

A coroner's inquiry in August 2013 found he had died from an acute allergic reaction to zinc chloride, a key compound used in smoke grenades.

Mr Goh told The Straits Times yesterday that Capt Chia is also saddened and affected by the incident.

"My client sincerely hopes that the family of the late Dominique will finally have a closure over the matter and move on with their lives," he said.

Pte Lee's mother Felicia Seah told The Straits Times: "What we want is justice, what we want is closure. For four years, we cannot get any closure."

In a statement last night, the Ministry of Defence said it and the SAF will continue to provide support to Pte Lee's family.