London ? Britain’s government wants to quickly deploy full body scanners at U.K. airports to fight an expanded terrorist threat, but privacy concerns — and fears that children may be exploited — seem likely to slow the plan.

Privacy campaigners and children’s rights groups say the technology, now being tested at Manchester Airport, violates British and European law by producing sexually explicit images of children.

They say the machines cannot be allowed because they can clearly show a child’s genitalia when a boy or girl walks through the airport scanners, which are designed to reveal concealed liquids, explosives or weapons to assure the safety of commercial air travelers.

Ian Dowty, legal adviser to Action on Rights for Children, said he believes it would be a criminal offense to operate the scanners or to direct anyone to operate them if they are used to produce images of children under the age of 18.

“If anything produces an indecent image of anyone under 18, that is unlawful and is in fact a criminal offense,” he said. “As we’ve seen on the Internet, these machines clearly show genitalia, that in our view must result in an indecent image by any definition.”