[UPDATE: July 10]
In response to AsiaOne’s queries, the National Parks Board (NParks) said it was alerted to a sighting of a crocodile near Yishun Dam.
NParks group director for wildlife management How Choon Beng said it is likely to be an estuarine crocodile, also known as the saltwater crocodile.
This crocodile species is known to be seen in the Straits of Johor, he added.
"We are monitoring the sighting and have placed advisory signs around the area to warn public to stay away from the water’s edge," How said.
Kayaking operators and other stakeholders have also been advised to avoid the waters.
Saltwater crocodiles are the largest crocodile species in the world and can grow to up to 6 to 7 m in length.
They inhibit brackish and freshwater areas and are usually found in the water or on mudflats away from visitor routes.
Some visitors to the Yishun Dam were greeted by the sight of a crocodile leisurely gilding through the waters on Sunday (July 7) morning.
Taking to Facebook page Singapore Wildlife Sightings on early Monday morning, user Toh Wilson posted an over one-minute-long clip showing the reptile swimming some distance away from the shoreline.
The Straits of Johor can be seen in the background.
A man can heard saying in the video that he often visits the dam, but "seldom sees" crocodiles.
The clip has since gone viral, amassing over 180,000 views at the time of writing.
Netizens were amazed by the video, with several commenting that the reptile is "big" in size.
Some also poked fun at the location of the spot, with one user commenting: "Yishun, so happening even buaya (crocodile in Malay) also go there."
A few netizens voiced concern about the potential danger that visitors might be in, and cautioned the public to be careful.
"This is so unsafe. Authorities need to put a signage around this place to warn the public," said a Facebook user.
"Fisherman or anyone wading around the shallows or edge of water better [be] careful. They are faster than you think and can wait patiently underwater until the prey appears within striking distance," wrote another.
However, others countered that crocodiles are "timid" and advised the public to "leave it alone".
Said one netizen: "I know we are afraid... but we must educate humans not to enter the water or go near the banks instead of removing the wildlife so that we can stand there. It’s their home to begin with."
According to the NParks website, members of the public who encounter a crocodile should stay calm and back away. They should not approach, provoke or feed the animal.
They can call NParks' Animal Response Centre at 1800-476-1600 to report the sighting, or if any assistance is required.
Last October, a nearly 3m-long saltwater crocodile was spotted at Marina East beach. It was later trapped at East Coast Park and then put down due to public safety concerns.
How Choon Beng, director of wildlife management and outreach at NParks, told the Straits Times then that the reptile could not be relocated due to a risk of it returning to the park.
In December 2022, a saltwater crocodile was seen near West Coast Park, prompting authorities to put up warning signs near the waters.