HALIFAX -- A mysterious Friday night incident in which a Canadian Coast Guard vessel ended up on its side and partially submerged in water at a Nova Scotia shipyard is now being investigated as suspected vandalism.

Halifax Regional Police officers responded to the Canadian Maritime Engineering shipyard in Sambro at around 9:30 Saturday morning, where CCGS Corporal McLaren had slid down a ramp and hit the water overnight.

"Preliminary investigation revealed that someone damaged the slip, which caused the ship to slide back into the ocean," said Sgt. Pierre Bourdages in an email.

"The extent of the damages to the ship is not known at this time."

CCGS Corporal McLaren was at the Sambro shipyard for scheduled maintenance.

The alleged vandalism came as an unpleasant Saturday morning surprise for Dean Mitchell, marine services manager at the shipyard.

In an interview Saturday, he said officials discovered that a cable on the ship's cradle and an additional safety cable had been cut clean through.

"I'm very concerned," he said, adding that he estimates the coast guard will be "down a vessel" for as much as six months or more as repairs are completed.

What made the problem worse, said Mitchell, was that parts had been taken out of the ship's hull for refit, creating holes in the boat that swallowed up water and caused it to partially sink.

Mitchell estimates it will cost as much as $5 million dollars to repair the vessel and the cradle.

"It's horrible all the way around," he said.

He believes the incident happened between midnight and 7 a.m. Saturday morning, adding that the shipyard is reviewing its security tapes to pinpoint the exact time it happened.

Jocelyn Lubczuk, press secretary for the minister of Fisheries, Oceans and the Canadian Coast Guard, said coast guard officials were on scene Saturday and are establishing a damage assessment and salvage plan with the shipyard.

She said there were no injuries and a floating barrier has since been put in place to prevent environmental impacts.

"The protection of our mariners and our marine environment remains a top priority for our government, and we thank the Canadian Coast Guard for their timely and effective response," Lubczuk said in an interview.

She said it will be an estimated three to four days before CCGS Corporal McLaren is returned to the slip.