A British Columbia man is lucky to be alive after a black bear attacked him as he sat in the hot tub at his Whistler timeshare.

Coquitlam insurance agent Dave Anderson was sitting in the outdoor hot tub Sunday afternoon when all of a sudden, he felt the bear hit him across the back of his head.

"I was sitting in one corner of the hot tub, unfortunately with my back to the ravine, and all of a sudden was smacked across the back of the head," Anderson told CTV British Columbia in an exclusive interview.

"I hadn't heard anything. And it knocked me forward into the hot tub. I turned around as I was sort of falling forward and saw a large male black bear."

Anderson scrambled out of the hot tub as the bear attempted to get in, and ran inside the house. Anderson sustained deep cuts to the top and back of his head, one of which required 18 stitches.

His wife, Val, called him "the luckiest unlucky man around," and described her husband's cry for help.

"I heard him yell bloody murder and I went tearing down the stairs and at that point he had slammed the patio door and said that a bear got him," Val Anderson said.

She called 911 as the bear paced outside the patio door for about eight minutes before ambling away.

Whistler police arrived on the scene, found the bear about 100 metres away and destroyed the animal.

Conservation officials are performing a necropsy on the bear to determine why a seemingly healthy animal would attack without provocation.

"The circumstances are unusual in that first of all the bear approached a person it didn't have to approach, injured a person it didn't have to injure and then it lingered and then showed some interest in the person who was on the other side of the sliding glass door," said Insp. Chris Doyle, a conservation officer. "So obviously that kind of behaviour is of some concern."

While many bears in the Whistler area are tagged, the one involved in Sunday's attack was not. A preliminary examination of the animal showed it had been consuming food it found in its natural habitat, meaning it wasn't hungry and foraging for garbage.

"We weren't cooking bacon out there or dangling salmon around or anything," Val Anderson said. "He didn't even have a glass of water. So I'm not sure what attracted him to the hot tub."

Conservation officials speculate the bear may have been attracted by the hot tub cover, which, to a bear, can smell like ant larvae.

Dave Anderson said in future, he won't sit in his hot tub with his back to the woods.

"Not by myself, at least," he said. "I'll have somebody facing the ravine as well to keep an eye out."

With a report from CTV British Columbia's Shannon Paterson