The body of a man was found at Sentosa's Tanjong Beach on Saturday morning.
Police said they were alerted at 7.16am and found the body at the shoreline.
Paramedics from the Singapore Civil Defence Force (SCDF) pronounced the man dead at the scene.
The SCDF said it responded after being alerted to the incident at 120 Tanjong Beach Walk.
The Straits Times understands that the dead man appeared to be in his 40s and showed no visible signs of injury. While the cause of death is still unknown, the condition of the body is consistent with drowning.
Video footage provided to citizen journalism site Stomp shows an area of the beach cordoned off with police officers on site. In it, a blue police tent - usually used to cover a body - can be seen on the sand.
The case has been classified as an unnatural death and is being investigated by the police.