OTTAWA - Group sex among consenting adults is neither prostitution nor a threat to society, the Supreme Court of Canada ruled on Wednesday as it lifted a ban on so-called “swingers” clubs.

In a ruling that radically changes the way courts determine what poses a threat to the population, the top court threw out the conviction of a Montreal man who ran a club where members could have group sex in a private room behind locked doors.

“Consensual conduct behind code-locked doors can hardly be supposed to jeopardize a society as vigorous and tolerant as Canadian society,” said the opinion of the seven-to-two majority, written by Chief Justice Beverley McLachlin.

The judges said that just because most Canadians might disapprove of swingers’ clubs, this did not necessarily mean the establishments were socially dangerous.

“The causal link between images of sexuality and anti-social behavior cannot be assumed. Attitudes in themselves are not crimes, however deviant they may be or disgusting they may appear,” the judges said, noting that no one had been pressured to have sex or had paid for sex in the cases the court considered.

“The autonomy and liberty of members of the public was not affected by unwanted confrontation with the sexual activity in question ... only those already disposed to this sort of sexual activity were allowed to participate and watch,” they said.

They also dismissed the idea — raised during Labaye’s original trial — that group sex was dangerous because it could result in the spread of sexually transmitted diseases.

“Sex that is not indecent can transmit disease while indecent sex might not,” they ruled.