The Royal Canadian Mounted Police also refused to elaborate why a roadblock had been set up outside the ghost town of Sundance, near Gillam, where Bryer Schmegelsky (18) and Kam McLeod (19) torched their getaway car and disappeared two weeks ago.
The RCMP divers searched the Nelson River near Gillam over the weekend after an abandoned and damaged aluminium rowboat was spotted by a helicopter.
"The Underwater Recovery Team has completed their work following the discovery of a boat on the shore of the Nelson River," the RCMP announced in a tweet.
"They will not be conducting any additional dives.
"A police roadblock has been put in place today in the Sundance, MB (Manitoba), area for ongoing search efforts."
AAP asked the RCMP if the divers found any clues to help in the search for Schmegelsky and McLeod.
"We aren't releasing any additional info about the dive, boat or roadblock today," RCMP's Robert Cyrenne replied to AAP in an email.
Some Canadian media organisations reported the divers did not find anything, but the RCMP declined to clarify if the reports were correct.
It could be the latest dead end in the three-week nationwide hunt for Schmegelsky and McLeod that began in the western Canadian province of British Columbia and has spanned more than 5000km east over three other provinces.
Mr Fowler, 23, the son of a high-ranking NSW police officer, and his girlfriend Chynna Deese, 24, were found shot dead in a ditch on the side of a BC highway on July 15.
The body of botanist Leonard Dyck was discovered four days later on another BC highway and 2km away from an abandoned and burning pick-up truck Schmegelsky and McLeod had been driving.
Schmegelsky and McLeod drove a grey Toyota RAV4 3000km east to Gillam before setting it alight in bushland.
The RCMP have not announced a single confirmed sighting of the duo since.