The U.S. government was sued in federal court in Boston by two Harvard University law students who claim their constitutional rights were violated by “nude body scanners” and “enhanced pat-downs” at airports.

Jeffrey Redfern, 27, and Anant Pradhan, 23, who are members of the law school’s class of 2012, said the security measures taken at airports are “intrusive” and violate the Fourth Amendment of the U.S. Constitution, according to their complaint filed Nov. 29.

The students, who said they are regular travelers who use Boston’s Logan International Airport, seek a declaration that mandatory screening using the enhanced measures is unconstitutional and a ban on the techniques “without reasonable suspicion or probable cause.”

More than 400 body scanners, which are designed to detect non-metallic weapons beneath clothing, have been installed in at least 70 U.S. airports. Fewer than 50 were in use a year ago, the Transportation Security Administration has said.

The TSA has accelerated adoption of the scanners since a Northwest Airlines passenger tried to blow up a flight to Detroit on Dec. 25 by igniting explosives in his underpants. The bomb failed to fully detonate.

The scanners in use at airports produce images of the nude body. Travelers who don’t want their bodies scanned can receive an “enhanced pat-down” by airport security staff.

Pradhan, traveling from Boston to Dallas on Nov. 24, and Redfern, flying to Washington from Logan on Nov. 17, opted out of the scanners and were given pat-downs, according to the complaint.

‘Genitals and Buttocks’

“Plaintiffs found the process highly intrusive, including touching, better described as prodding and lifting of the genitals and buttocks,” they said in the suit.

Named as defendants were Janet Napolitano, Secretary of Homeland Security, and John Pistole, administrator of the TSA.

Amy Kudwa, a spokeswoman for the Department of Homeland Security, declined to comment and referred calls to the TSA. Sterling Payne, a spokeswoman for the TSA, declined to comment on pending litigation.

“I don’t think Anant and I want to enter the public fray any more than we have to –especially during finals period,” Redfern said yesterday in an e-mail.

“We honestly don’t have much to say that would be of general interest,” he said. “So much has been said about this issue in the last month, and while we think we have some solid legal theories, they would be terribly boring to anyone but a lawyer.”

The case is Redfern v. Napolitano, 10-cv-12048, U.S. District Court, District of Massachusetts (Boston).

© Copyright 2010 Bloomberg News. All rights reserved.