LONDON – Britain’s pornographers are breaking the law if they sell adult videos over the Internet or through the mail, the High Court ruled on Monday.

Two pornography companies had argued that a law banning the sale of videos by post was an “unjustified interference with freedom of expression.”

But Lord Justice Maurice Kay, upholding a lower court ruling, said it was a legitimate way to help prevent pornography being sold to children.

“We have no doubt that one of the main reasons for the restriction is to ensure that the customer comes face-to-face with the supplier so that there is an opportunity for the supplier to assess the age of the customer,” he said.

The restrictions were therefore “lawful, necessary and proportionate” under the Human Rights Act.

The two porn merchants had argued that videos sent out in the post had effectively been purchased from licensed sex shops that dispatched them, but the judges rejected this argument.