Since mid-February, staff at the Pasqua have noticed a discolouration in a layer of cotton wrapping as surgical tools are put through a steam sterilizer.
Last week, the health region decided to cancel all surgeries at the Pasqua for ten days to allow time to determine the cause of the discoloration and find out if it has any impact on patients.
Since that time there have been 80 surgical and 22 procedural postponements.
The Regina General Hospital has also seen 13 additional surgeries, with nine others transferred to private facilities.
Health region CEO Keith Dewar says his team has been working hard to figure out the mystery.
"We've been working our way through various potential causes including the sterilizers themselves, the way we process our water into steam, and how it gets transferred into the machines," he said Monday. "We've been looking at cleaners and a number of other potential sources, including the linens."
So far no cause has been identified. Dewar noted, however, that some of the packs have reacted to the staining more than others.
Testing has shown that no metallic residue has been left on the equipment itself, which Dewar said is further indication there is no risk of harm to patients. More test results still have to come in regarding organic matter.
"As we learn more about what it is not, and what's not in the equipment...we are considering options in terms of rebuilding our capacity at the Pasqua. We have no time for that to occur yet."
Surgeries have been postponed up until Thursday. Dewar said the decision on whether more should be postponed will be made later.