SINGAPORE - Investigators had found lapses in Underwater World Singapore's (UWS) safety measures after a stingray fatally stung one of its divers in 2016.

Among other things, a district court heard on Thursday (Jan 14) that the now-defunct Sentosa attraction had failed to provide adequate recovery procedures in emergencies during diving operations.

UWS had also failed to implement a system to document checks on diving equipment before they were used.

The court, however, heard that the lapses had not resulted in Mr Chan Kum Weng's death.

The 62-year-old man and his colleagues were trying to catch a leopard ray at around 2.30pm on Oct 4, 2016, when it suddenly attacked him.

The stingray's venomous barb on its tail pierced his chest and he was pronounced dead later that day.

On March 1, 2017, then State Coroner Marvin Bay found Mr Chan's death to be a tragic misadventure.

UWS, which was owned by Haw Par Leisure, admitted in a district court on Thursday that it had failed to take necessary measures to ensure its workers' safety. It pleaded guilty to an offence under the Workplace Safety and Health Act.

Mr Chan had been working for UWS for 25 years. The attraction had appointed him to plan and execute the capturing of marine animals before and after it closed its doors for good.

UWS ceased operating in June 2016.

Ministry of Manpower prosecutor Mohd Rizal said that it was in the process of vacating its premises in Siloso Road when the tragedy occurred four months later.

Mr Chan and his colleagues were trying to capture the leopard ray in a reef tank to be transferred to another tank.

After the ray stung him, he was taken to the Singapore General Hospital, where he died of a "penetrating injury to the chest by a stingray barb" at around 3.30pm that day.

Following this tragedy, investigations revealed that UWS did not document the safe work procedures for the capture of marine animals.

Mr Mohd said: "The said activity was mainly undertaken by (Mr Chan) and he would plan and execute the capturing works, which included briefing on the capturing methods he had devised, the allocation of manpower required, equipment needed and the foreseeable risks and precautions to take during capturing.

"Investigations further revealed that no standby diver was appointed in the case of an emergency... Should a diver encounter an emergency situation, such as loss of consciousness, it would not be picked up by the buddy diver immediately as there was no line of sight or any form of lifeline provided."

On Thursday, Mr Mohd urged the court to sentence UWS to a fine of at least $150,000, stressing that there was also no system for pre-diving equipment checks at the attraction.

UWS will be sentenced on Feb 25. For committing the offence, UWS can be fined up to $500,000.