The famed but elusive Brahman bull on Coney Island died last month during a routine health check.

The National Parks Board (NParks) said yesterday that the animal could not be revived after it was sedated for blood and faecal samples during its annual health check by veterinarians on Sept 28.

NParks is making the announcement only now as post-mortem investigations by the Agri-Food and Veterinary Authority have just concluded.

The results showed that the bull had chronic underlying illnesses, and that it had probably died of heart and lung complications while sedated.

"Health checks are necessary for its own well-being and for public health reasons, for example, to prevent the spread of diseases between animals and humans," said NParks in a statement.

The agency added: "Given its large size, sedating it was a standard procedure to ensure the safety of all personnel involved."

It was a mystery how the bull had found its way onto the island in the first place, and its age is unknown. NParks first found it while in the process of setting up the 50ha Coney Island Park.

The park, connected by two bridges to Punggol Promenade and Pasir Ris Coast Industrial Park 6, was opened to the public last October.

The animal was sickly and malnourished when it was first found, but recovered after foraging naturally on the abundance of vegetation on the island.

"It was a recognisable part of Coney Island Park and will be missed," said NParks.

However, few visitors had actually set eyes on the elusive, doe-eyed animal.

Marketing executive Cheryl Goh, 26, had not seen it on her trip to Coney Island last year but was sorry to hear it had died.

She said: "The mystical nature of its origins, and the fact that it had survived alone and stranded, made it so much more special."

Healthcare worker Gao Kaihui, 28, had been hoping to see the bull during a trip to the park next week.

"I guess it was probably old, and NParks had done its duty of providing as much as it could since knowing of its existence," she said.

"It is probably the only lucky bull that has roamed free in Singapore's vastly fast-developing concrete city."

Audrey Tan