RCMP say there are signs pointing to foul play in the case of a missing Cape Breton fisherman whose boat was found overturned at the mouth of the Petit-de-Grat harbour early Saturday.

Investigators say Phillip Joseph Boudreau was last seen Saturday morning at approximately 6 a.m. His overturned boat was spotted overturned near the wharf around 7:30 a.m.

Divers and search crews have been scouring the area for the 43-year-old man.

“There hasn’t been any sign of Mr. Boudreau, unfortunately,” says Sgt. Mark MacPherson, a spokesperson for St. Peter’s RCMP. “At this time, we have our dive team looking for any evidence.”

The RCMP’s major crime unit has been called in to investigate reports of an alleged altercation involving a large fishing vessel and Boudreau's boat before he disappeared.

Sgt. Mark MacPherson, a spokesperson for St. Peter’s RCMP, says police are conducting interviews and trying to piece together what happened.

“Well, in a situation like this, where we believe an altercation occurred, we have to keep in mind that it could have been a criminal act that resulted in this man’s disappearance,” says MacPherson.

Police have seized the fishing boat they believe may have been involved in the dispute with Boudreau. It is now under RCMP guard at a wharf in nearby Arichat.

Police say they are speaking to those who were on the vessel but haven’t laid any charges.

“We are conducting interviews with the other people that were on that other vessel,” says MacPherson. “They’re just interviews at this time. That’s all I can say about that.”

MacPherson wouldn’t confirm whether police are investigating a report of gunshots heard around the time of the dispute.

“I can’t confirm or deny gunshots being fired or having been involved with this,” he says.

Many community members are expressing shock and sadness over the incident, as rumours circulate about what may have happened during the alleged altercation.

“Fishing…there’s altercations going on all the time,” says local fisherman Logan Landry. “There’s not good conversations, let’s just say, but everything is rumours. This is such a small community. It’s really a nice community. It’s a shame that it had to come to something like this.”

“It’s very disturbing that something like this is happening,” says area resident Phil Benoit. “It’s an awful thing, not only for us, but for fishermen too.”

Police say their search is now a recovery mission, as the length of time someone could survive in water so cold has long since elapsed.

Boudreau’s neighbours say they hope his body will soon be found.

“So it would be over and dealt with. It’s an awful thing for a small community,” says Benoit.

The RCMP dive team is expected to return to the waters on Tuesday.

With files from CTV Atlantic's Dan MacIntosh and Ryan MacDonald