Nurse Leslie Warner will never forget being taken to her local RCMP detachment in Fernie, B.C., in 2022 and charged in a social security fraud operating out of Alberta.

She says she was fingerprinted and had her mug shot taken.

"I was like: 'Oh my God, this is my identity theft,'" Warner recalls telling police. "I did not do this."

The fraud charges were dropped soon after she explained that an imposter had been using her identity since 2020, when someone hacked into her Canada Revenue Agency account and filed a bogus return in Alberta that stated tax preparation company H&R Block was her new "authorized representative."

But Warner had never authorized H&R Block to file her taxes.

Warner said she has been trying for years to understand how her identity — and at times her life — came to be hijacked. She is also still "nervous" about her CRA account being hacked again.

The Fifth Estate has learned that Warner's name is one of thousands included in a massive breach of employees' personal information — including social insurance numbers — from the British Columbia government's Interior Health authority, which runs hospitals and medical facilities in the southeastern part of the province.

Kelowna General Hospital is one of many facilities operated by Interior Health — a B.C. agency that provides health services to almost 900,000 people living between the province’s coastal mountains and the Rockies. (Thomas Popyk/CBC)

While it is unclear how many of those names were exploited by fraudsters, The Fifth Estate has found that stolen identities from several Interior Health employees — past and present — have been used to obtain bogus CRA refunds and fraudulent loans in the past several years.

A former Ontario privacy commissioner says "it could be a nightmare" for individuals whose names and private identification are included in the breach.

"This is horrible," said Ann Cavoukian, executive director of the Global Privacy and Security by Design Centre.