Police are investigating a knife which was found with what seems to be human hair near Whampoa River.

Factory worker Qu Yong, 48, had discovered the knife on Sunday at about 5 pm, when he went to the area to spot fishes. He was standing under a bridge at the Whampoa River near Block 5 St George's Lane when he saw a dragon handle on the grass patch.

"I thought the dragon handle looked interesting. Then when I pulled it out, I realised it was a knife," said Mr Qu in Mandarin. "There were maggots and black hair on it."

The knife, he said, looked at least 40 cm long and was wrapped in paper and yellow tape. It was a bit dirty, but had no blood stains and did not smell bad.

Mr Qu then called his friend, a 57-year-old general worker who wanted to be known only as Mr Seah, to meet him.

Mr Seah said the hair was wrapped around the handle of the knife.

"I didn't want to go closer to the knife after he told me that there was hair on it," said the St George resident.

Mr Seah then lodged a police report on behalf of Mr Qu, who does not speak English.

The duo then led the officers to the scene, and were subsequently taken to Police Cantonment Complex to have their statements taken.

Police declined to comment if the knife is related to the murder of 33-year-old beautician Jasvinder Kaur, citing ongoing investigations. Her body - without her head and hands - was found wrapped in trash bags and floating in a waterway between McNair and St George's Road in December last year.

A forklift driver, Gursharan Singh, 25, was subsequently charged with murdering Ms Kaur. The police are still looking for her husband, logistics executive Harvinder Singh, 33, who had skipped town before her body was found.