04/14/2014 08:49 EDT | Updated 06/14/2014 05:59 EDT

How did U.S. customs get Ontario health information?

Ontario's privacy watchdog will release a report this morning that probes whether private health information of Ontarians is being shared with U.S. Customs and Border Protection agents.

Privacy commissioner Ann Cavoukian's report was triggered by last fall's news that some Canadian travellers with a history of mental-health issues had been denied entry into the U.S.

Ellen Richardson was turned away at Toronto's Pearson airport by U.S. customs agents because she was hospitalized in June 2012 for clinical depression.

She attempted suicide in 2001 by jumping off a bridge, leaving her a paraplegic. But her mental health has since improved with medication and professional help from a psychiatrist, she said.

The border agent cited the U.S. Immigration and Nationality Act, which denies entry to people who have had a physical or mental disorder that may pose a "threat to the property, safety or welfare" of themselves or others, she said.

Richardson said it's "ridiculous" she was denied entry to the U.S. and maintains that she's not a threat to anyone. Richardson is also an author of a book, Hope for the Heavy Heart, in 2008 about her struggles with depression.

Last fall, Richardson told CBC News that border guards referenced her 2012 hospitalization, and not her book, in denying her entry into the U.S. Richardson's stay in hospital was preceded by a 911 call, placed by her mother, but she says police were never involved, only an ambulance.

Lois Kamenitz, 65, of Toronto contacted Psychiatric Patient Advocate Office in Toronto last fall after U.S. customs officials at Pearson Airport prevented her from boarding a flight to Los Angeles on the basis of her suicide attempt four years earlier.

A U.S. customs officer told Kamenitz that he had information that police had attended her home in 2006.

These and other cases raised concern with Cavoukian about how private health care information was shared with U.S. border services.

Since Richardson's case became public, more than a dozen Canadians have told the Psychiatric Patient Advocate Office in Toronto that they had been blocked from entering the United States after their records of mental illness were shared with the U.S. Department of Homeland Security.

U.S. border guards are allowed to bar anyone they deem a threat to themselves, others or their property. They have access to police records — including even uneventful encounters with officers — but medical records are supposed to be held in the strictest confidence.