Cape Breton Regional Police are saying little about a search along the banks of Renwick Brook in Glace Bay, which is now into its second day.
Investigators scoured the banks on Wednesday afternoon and were back at the scene on Thursday, but police would not say what they were looking for or the reason for the search.
Cape Breton Regional Police have also set up an enclosure along the banks and are heating the inside with propane heaters.
Sources have told CBC News the search is related to an active homicide investigation.
There are currently three active homicide investigations involving victims from in and around the Glace Bay area.
Brett Elizabeth MacKinnon was last seen in June 2006 and her skeletal remains were found more than two years later by hunters in a wooded area just outside of Glace Bay.
John Wayne Hynes, of Glace Bay, was charged earlier this week with accessory after the fact in the 21-year-old woman's death.
In September 2006, Harold Slaunwhite was found dead in his Dominion home by a relative. The 82-year-old man was a veteran of the Second World War.
No one has been charged in the case.
Most recently, 21-year-old Laura Jessome went missing from the New Aberdeen area of Glace Bay in May. A hockey bag containing her remains was found floating along the Mira River near Marion Bridge several weeks later.
Morgan James McNeil, of Glace Bay, is charged with second-degree murder in Jessome's case.
Brian Augustine Deruelle and Robert Edwin Matheson — also from Glace Bay — are charged with accessory after the fact in the same case.