VANCOUVER – Canadian authorities are investigating allegations that 100 sled dogs were cruelly shot to death because tourism slowed after the 2010 Vancouver Olympics, officials said on Monday.

The animals hauled tourists on backcountry sled trips near the Olympic-host community of Whistler, British Columbia.

The dogs appear to have been "slaughtered" inhumanely in April, shortly after the Winter Games ended, according to an animal protection group investigating the incident.

The incident became public after an employee of Outdoor Adventures Whistler filed a compensation claim with the province, saying he was suffering from stress after being forced to shoot the animals and bury them.

Multiple shots were needed to kill some dogs, others were killed as they attempt to flee, and some were still alive when they were dumped in a mass grave, CKNW radio in Vancouver reported, quoting the worker's compensation claim.

The man said he was told to kill the animals, which were part of a pack of 300 dogs, because tourism demand has slowed, CKNW reported.

It is legal for an owner to kill an animal in British Columbia, but it must be done humanly, said Lorie Chortyk, general manager of the British Columbia Society for the Prevent of Cruelty to Animals.

"This doesn't appear to meet any standard of what is humane. ... This appears to be a slaughter," said Chortyk, whose agency investigates animal cruelty cases and has the authority to recommend criminal charges.