Airport body scanners that are already in place at Manchester and Heathrow airports may be against the law, the Equality and Human Rights Commission has warned.

Chairman Trevor Phillips said the scanners may be breaking discrimination law and breaching passengers’ privacy. He has written a letter to transport secretary Lord Adonis asking him to address these concerns.

In the letter, the commission said it recognised the threat posed by terrorist activities but expressed concerns about the “apparent absence of safeguards to ensure the body scanners are operated in a lawful, fair and non-discriminatory manner”.

Phillips said: “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.”

The controversial scanners are being introduced following an attempted terrorist attack on a Delta flight on Christmas Day last year.

Last week, Lord Adonis stressed that all images captured by the scanners would be deleted immediately.