The RCMP are investigating allegations that a surgical tool was purposely tampered with at Royal Inland Hospital in Kamloops.
The investigation will focus on an incident that occurred April 14, RCMP said.
"The incident is being described as very obvious and intentional," said Const. Cheryl Bush. "The RCMP were called after Royal Inland Hospital staff made the discovery, and they assure the equipment was discovered prior to being used [for surgery]."
Bush did not specify what the instrument was or what had been done to it.
About 150 surgeries were cancelled and another 250 postponed in February when instruments contaminated with such things as blood and bone fragments turned up in the hospital's operating rooms.
Health officials later said they'd solved the problem with improved supervision and training.
"Unlike incidents earlier in the year, what was discovered was different than what had previously been seen," hospital administrator Marg Brown said Tuesday.
"In this particular incident, we believe there was tampering involved, and subsequently called the RCMP."
Brown said the tools are sterilized in a controlled area accessed by more than 60 employees.
"I am confident we are safe to proceed [with surgeries]," she said, adding further precautions have been put in place.