Thieves used bear spray and wore gas masks when they stole 12 pieces of Bill Reid art from the Museum of Anthropology this weekend.
In an interview with the CBC, museum director Anthony Shelton said several key surveillance cameras stopped recording about four hours before the theft, which occurred while the lone security guard was on a smoke break.
The thieves, wearing gas masks, fired bear spray in the museum.
Shelton said an electronic alarm that alerted campus security was tripped when the cameras went offline, but no action was taken.
The burglary was not discovered until a security guard shift change at about 9 a.m. Saturday.
Shelton said police have been questioning staff, but said there is no evidence to suggest it was an inside job.