Stuck near the opening of a monsoon drain at the Whampoa River were two plastic bags - a black bag about the size of an adult body and a smaller white one.
They caught the eye of two women who were on a path next to the river at about 7.30am on Thursday. They thought a leg was sticking out of the black bag and called the police.
When it was recovered from the water, there was indeed a body inside, but its head and hands were missing.
The female body was topless and clad only in a pair of black pants.
The New Paper understands that the hands are still missing, but it is not known if the head has been found.
It is also not known what was in the white bag.
No identification was found on the body, which is said to be tanned.
Residents at McNair Road and St George's Lane, situated near the river, were surprised to see about 20 policemen combing the area and four officers from the Singapore Civil Defence Force (SCDF) wading in water near Block 110.
Civil servant Adeline Ng, 39, took pictures of the scene and sent them to citizen journalism website Stomp.
She told TNP that she spoke to a jogger who had seen the bags with another resident.