KOTA KINABALU (THE STAR/ASIA NEWS NETWORK) - A huge fish weighing more than 100kg was found floating in a lake in the Malaysian state of Sabah.

The fish, which was found at the Tun Fuad Stephens lake in Sabah's capital city of Kota Kinabalu, caused excitement among the public and anglers.

The 108kg fish, measuring about 2.4m in length, was identified as arapaima, a native of the Amazon River.

It was discovered by joggers at about 6.30am on Monday (Aug 5).

A photo of the fish, which was widely circulated on social media, piqued the interests of locals, who asked whether the once-protected lake was now open for fishing.

Mayor Nordin Siman said the park was still under City Hall management and no one was allowed to fish at the lake.

"The fish was already dead when joggers spotted it, and we sent people to check it out," he said.

He added that officials from the Fisheries Department and a research team from Universiti Malaysia Sabah will find out the cause of the fish's death.

For now, they believe it could be due to old age.

Asked how a fish from a species that originates from the Amazon ended up in the lake, Datuk Nordin said a fish breeder might have released it in there years ago, as the person could no longer take care of it.