PETIT-DE-GRAT, N.S. -- Police in Cape Breton took over the search Sunday for the body of a man missing since his boat overturned and were also investigating witness reports of an altercation on the water.

RCMP Sgt. Mark MacPherson said there had been no trace of Phillip Joseph Boudreau, 43, of Petit-de-Grat, since his four-metre long open boat was found near the mouth of the community's harbour early Saturday.

MacPherson said after a day-long search officials with the Joint Rescue Coordination Centre in Halifax had turned responsibility over to the RCMP. He said military searchers believed there was little chance the missing man had survived the mishap given the time elapsed since the search began.

"They thought that window had closed, therefore the RCMP took over," he said.

MacPherson said a ground search was continuing and an RCMP dive recovery team would also be in the water for as long as conditions would allow.

He said police were also investigating reports from witnesses of "some sort" of an altercation involving Boudreau's boat and a fishing vessel.

"We began to investigate further and take statements and that continues at this time."

MacPherson wouldn't comment on whether arrests or charges were being considered.

He said the search would continue as long as weather and sea conditions were favourable.

"I anticipate us being here for several days -- two or more days both on the land and on the water," he said.