Employer/Employee Rights Regarding Information in Manitoba

Roughly, where can I find out what rights / responsibilities a private-sector employer has when faced with a request from an employee for medical information provided to the employer by the employee?

For instance: Jack gives his empoyer a copy of a doctor’s note, a few months later Jack asks his employer for a copy of the note. Must the employer provide a copy or is it prohibitted under legislation somewhere?

PIPEDA doesn’t seem at all relevant as we are not a federally regulated workplace (banking, transport etc.) and I couldn’t find the information in the Privacy Act (likely because I’m not a lawyer).

Please don’t furnish advice but please do point me to the correct legislation and a ballpark of which article or section in which to look.

I have aksed GFactor if this question passes and he has okayed it.