Call it a case of seduction for a good cause.

A New England bone marrow registry is under investigation after using models in short skirts and lab coats to convince members of the public to submit to a bone marrow sample.

What the models allegedly did not tell the donors -- who were told they could potentially save a life by signing up -- is that their health insurance would be charged $4,300 for the procedure.

Caitlin Raymond International Registry, a group that works to match bone marrow donors with those in need of a transplant, allegedly spent $40,000 to $50,000 a week hiring models to work booths at malls and sports events, convincing passersby -- mostly men -- to submit a to a DNA swab, the Nashua Telegraph reports.

People who volunteered for the test say the models told donors they wouldn't be charged for the test -- but under state law, the full cost of the test would be charged to the person's insurer.

The New York Times describes how the registry went about collecting samples:

James T. Boffetti, [New Hampshire's] senior assistant attorney general, said the registry had hired models based on their photographs and had given them “explicit instructions” to wear heels and short skirts. The registry paid the models to approach potential donors at dozens of malls and events throughout New England, Mr. Boffetti said.

“The models worked the crowds, if you will,” he said. “We were told basically they would engage a lot of younger men with some sort of flirtatious thing: ‘Hey, don’t you want to be a hero? Come on, do this!'"

If people expressed interest, Mr. Boffetti said, the models — who, for reasons that remain unclear, sometimes also wore electric-blue wigs — would hand them off to registry employees who would take mouth swabs.

The alleged scam came to light when the city of Manchester, New Hampshire, which administers its own health insurance, received a bill for more than $8,000 after two city staffers were swabbed at the Mall of New Hampshire, the Times reports.

The registry and its affiliated hospital, UMass Memorial Health Care, which carried out the tests, have both agreed to stop operating pending the attorney general's investigation. Massachusetts Attorney General Martha Coakley is investigating as well.

The phenomenon of being charged for a bone marrow test is unique to New England: Massachusetts, New Hampshire and Rhode Island are reportedly the only states where health insurers can be charged for the procedure.