The use of body scanners at UK airports may be unlawful, the Equality and Human Rights Commission warned today.
Scanners already in place at Heathrow and Manchester Airports may be breaking discrimination law as well as breaching passengers' rights to privacy, the commission said.
It has now expressed its concerns in a letter to Transport Secretary Lord Adonis.
In the letter, the commission said it recognised the threat posed by terrorist activities but that it had concerns "about the apparent absence of safeguards to ensure the body scanners are operated in a lawful, fair and non-discriminatory manner".
It added that it also had "serious doubts that the decision to roll this (body scanning) out in all UK airports complies with the law".
The commission's chairman, Trevor Phillips, said today: "The right to life is the ultimate human right and we support the Government's review of security policies.
"State action like border checks, stop-and-search and full body scanning are undertaken for good reasons. But, without proper care, such policies can end up being applied in ways which do discriminate against vulnerable groups or harm good community relations.
"National security policies are intended to protect our lives and our freedoms, but it would be the ultimate defeat if that protection destroyed our other liberties."