OTTAWA -- The Supreme Court of Canada has upheld expansions to Canada's rape shield laws made by the Liberals four years ago.

In a 6-3 ruling today, the court says the expanded rules to further prevent a sexual assault complainant's past from being used against them in a trial are "constitutional in their entirety."

Rape shield laws were enacted four decades ago to prevent a complainant in a sexual assault case from having evidence of their sexual history used to discredit them.

The Criminal Code says evidence of a complainant's prior sexual activities that are unrelated to the charges at hand can only be admitted with permission of a judge following a private hearing, and cannot be used to infer that the complainant is less trustworthy or more likely to have consented.

In 2018, the Liberals expanded the definition of what that evidence includes to add communications of a sexual nature such as emails and videos, as well as documents about the complainant that are in the possession of the accused.

They also granted a complainant the right to participate in the screening hearing with the judge and be represented there by a lawyer.

In today's ruling, a majority of justices say the right to a fair trial does not guarantee an accused gets "the most advantageous trial possible" and that "ambushing complainants with their own highly private records" can be unfair and unhelpful in the search for the truth.

This report by The Canadian Press was first published June 30, 2022.