A 400kg crocodile, probably one of the largest to have roamed wild here in decades, has been found dead on the Kranji Reservoir grounds.
Fondly nicknamed Barney by anglers, its death has puzzled experts as the creature had seemed relatively young and healthy, and had no visible injuries.
National water agency PUB, which oversees the area, said it was informed about the dead reptile about three weeks ago.
The 3.6m-long saltwater crocodile was disposed of at a nearby farm.
More saltwater crocodiles - the world's largest reptile and known to be formidable predators - have been spotted in Singapore in recent years.
Last year, about 10 of them were found living in waters around the north-western coastline, up from two in 2008.
There have also been regular sightings at Sungei Buloh and around Kranji Reservoir, although PUB said none had been reported in Kranji in 2012 and last year.
A day after Barney was found dead in an area open to the public - but difficult to access - farewell messages popped up on popular angling website Fishing Kaki.
"Goodbye, Barney from Kranji," said one commenter, who posted a photo of its body in a cart.
The person added: "FishingKaki.com salutes you and we know your offspring will carry a torch for you. We heart you."
The cause of the reptile's death is unclear.
Mr Subaraj Rajathurai, director of Strix Wildlife Consultancy, said it is very rare for crocodiles in the wild to die of disease. They generally live about 70 years.
Mr Solomon Anthony, 36, a volunteer with the Sungei Buloh Wetland Reserve, said the creature did not look old. "It had a good set of teeth, whereas a very old crocodile would have lost almost all its teeth."
Experts say it is a pity that the body had gone to a farm, as researchers could have solved the mystery through an autopsy.
Knowing the cause of death was also important for public safety, in the unlikely event that it was killed by the reservoir water, they added.
PUB monitors raw water quality every day.
Mr Solomon said that the agency could have given the crocodile to a museum to be preserved through taxidermy, given its size.
Males of the species generally grow to 5m from snout to tail, and weigh about 450kg, although 1,000kg, 7m-long giants are not uncommon.
PUB said it monitors the reservoir every day and stops fishing at designated areas if crocodiles are spotted.
Since 1989, it has authorised a team of handlers to capture the reptiles alive and hand them to a farm in Kranji for safekeeping.
Twelve have been caught - the last in 2006.
"This measure was to prevent crocodiles from endangering workers and visitors to the reservoir," said director of catchment and waterways Tan Nguan Sen.
Anyone who spots a crocodile should keep away from it and not provoke it.
Once at a safe distance, they should contact PUB's 24-hour call centre on 1800-284-6600 or the Agri-Food and Veterinary Authority's Animal Response Centre on 1800-476-1600.