The B.C. Court of Appeal has reversed a lower-court ruling and certified a class-action lawsuit led by a man who says he and other sperm donors had their samples ruined by the University of British Columbia.

Howard Lam took the university to court after a power failure inside one of its freezers in 2002 rendered his sample immobile while possibly destroying its genetic material.

A B.C. Supreme Court judge denied Lam's lawsuit last year, ruling a class-action was not the best way to address the issues in the case.

But the Appeal Court said that ruling was in error, allowing Lam and all others who had sperm inside the freezer to move forward.

The freezer contained samples from men undergoing chemotherapy or other medical treatments that could affect their reproductive capacity and Lam said UBC breached its contract.

The university has denied it was negligent and said all clients signed a liability agreement before submitting samples, though it has been unable to find copies of that agreement for 25 of the men, including Lam.