One of western Canada’s largest rental property companies is warning tenants about a cyber security breach it says was discovered earlier this year.

In a letter to tenants on Aug. 19, also published on its website, Mainstreet Equity Corporation says on it discovered a third party had gained access to a portion of its IT infrastructure on May 21.

“Upon discovering this, we immediately undertook countermeasures to prevent any further unauthorized activity,” the company said.

“We have also retained third-party cybersecurity experts to assist with containment, remediation and to conduct a forensic investigation and we are working with external legal counsel to ensure we meet our legal obligations.”