A Sats Singapore officer is in a critical condition in the intensive care unit (ICU) after consuming food from Spize.
He ate the catered food during a Deepavali celebration on Nov 6.
The New Paper understands that his lungs and kidneys are affected.
He is one of 49 people who fell ill after consuming the food from Spize, causing 21 people to be hospitalised.
The licence of the Spize outlet at River Valley that supplied 88 bento sets for the occasion was suspended last Friday.
The celebrations were organised by security company Brinks Singapore and held on their premises.
The officer attended the event as he was deployed to Brink's Singapore, though the event itself did not involve Sats.
A Brink's Singapore spokesman said "a number" of their employees fell ill after eating the food that they catered for the celebrations, and that they are currently working closely with the public health authorities.
The National Environment Agency (NEA), Ministry of Health (MOH) and Agri-Food and Veterinary Authority released a joint statement last Friday saying they are investigating several cases of gastroenteritis traced to the consumption of food prepared at the restaurant at 409 River Valley Road.
The statement said they were notified of the cases on Nov 7 and conducted a joint inspection on the same day.
"Several hygiene lapses were observed, including leaving ready-to-eat food uncovered in a chiller, not providing soap for hand washing (soap dispenser was faulty) and slotting knives for preparing ready-to-eat food in the gap between the food preparation tables," said the statement.
"The suspension will be in place until NEA is satisfied that the public health risks have been addressed."
Mr Haresh Sabnani, 41, the co-owner of Spize, apologised to customers on Facebook.
In a reply to posts on the Spize Facebook page, Mr Haresh said they were aware of the 49 cases including the officer warded in the ICU after speaking to MOH on Friday.
He said: "We have immediately closed our River Valley outlet and will be disposing of all food items.
"The gravity of the situation is nothing we have experienced before and we seek your patience and understanding."
This article was first published in The New Paper. Permission required for reproduction.