A body was found in Lower Peirce Reservoir yesterday morning, resulting in the authorities cordoning off a trail in the area.
In response to queries, the police said they were alerted to the discovery of the body, later established to be male, floating in the reservoir at about 7.15am.
The police have classified the case as an unnatural death.
The body was retrieved from the reservoir and taken away by 11.30am.
A witness, who had been jogging in the area, told citizen journalism website Stomp yesterday that when he first saw the body, he thought it was a pile of rubbish floating in the water.
But he was shocked when a woman later told him that it was a body. He added that the area where he made the discovery was "quite far in" from the entrance of the reservoir.
In a video shared on Stomp, a crowd could be seen gathered along the boardwalk overlooking the water, as police officers arrived at the scene. Police investigations are ongoing.