Police are trying to determine if a headless body dragged from the River Wandle by police divers on Monday morning could have originated in Croydon.

Pathologists at St George’s Hospital were conducting a post-mortem on the unidentified man while police kept a 100m section of the river downstream of Plough Lane, Wimbledon, sealed off, at the time of going to press.

Unconfirmed reports suggest divers were back in the river, yards from the former home of Wimbledon FC, searching for a head on Tuesday morning.

Police are unclear if the heavily decomposed body broke up naturally or as a result of criminal behaviour. A homicide investigation is pending results from the post-mortem.

A passer-by walking along the towpath alerted police at 9.30am on Monday after spotting the body floating in the river yards from the new Sanctuary housing development.

Residents watched from their balconies as three police divers pulled multiple body parts from the waterway. Onlooker Chris Gray said: “There were two men in diving suits carrying one body part on a stretcher which I can only guess was the torso.

“Soon after a woman came past carrying a something else in a large plastic box. Again, it was difficult to make out, but I dread to think what was inside. The police were looking in a secluded part of the river so it was hard to see exactly what was going on.”

The Metropolitan Police marine support unit was at the scene again on Tuesday in addition to three CID officers and several other uniformed police sealing off the scene.

According to Theo Pike, chairman of the Wandle Trust, this is the first time in more than a decade that a body has been found in the river.

He said: “This really is tragic news. I’ve always thought the fact the river is so shallow and fast-lowing, it hasn’t been a suicide site. I’ve been involved with the Wandle for many years at it’s the first time I’ve heard of this kind of thing.”