The public inquiry into long term care heard that the disgraced nurse had previously been under investigation for medication errors and allegations of abuse which were later withdrawn.
The Ministry of Health and Long Term Care says it had conducted inspections regarding Elizabeth Wettlaufer long before she admitted to killing eight seniors.
Since then, the government department says it has made some policy changes.
Karen Simpson was the director of the long term care inspections branch and told the inquiry that at various times incidents involving Wettlaufer were inspected.
Wettlaufer is currently serving a life sentenced after she confessed to killing a total of eight elderly residents at two nursing homes.
Testimony from ministry officials and inspectors is expected to make up much of the week at the public inquiry in St. Thomas.
