Attorney General Jay Nixon filed the lawsuit in Circuit Court, accusing the company and Gonzaga University law professor Speedy Rice of deceiving the state in their use of inmates at Potosi Correctional Center.
Nixon accuses Benetton of fraudulent misrepresentation, trespass by deceit and trespass by exceeding the scope of consent. He is seeking compensatory and punitive damages.
The state thought the inmates were being interviewed for a project sponsored by the National Association of Criminal Defense Lawyers.
"Instead, we find out that the project is a part of a Benetton advertising campaign," Nixon said. "Clearly our prisons are not allowed commercial endeavors and prison officials would have never allowed entry had they been told the truth about the project."
The ads appeared in a supplement that accompanied the February issue of Talk Magazine. The supplement includes interviews with the inmates and asks such questions as "Do you consider yourself a lucky person?" and "Are you afraid of dying?"
The campaign is expected to continue through the year on billboards, posters and other media across the country, as well as in Europe and Asia.
Mary Still, a spokeswoman for Nixon, said the request for access to the prisoners was granted following a letter from Rice asking for access as part of a "project" by the attorneys group. The letter said the project was underwritten by Benetton but said nothing about an ad campaign, she said.
"The term he used was for a project on the death penalty," Still said.
Officials at Benetton, an $11 billion family owned company, have said they never intended to mislead anyone and only recently decided to expand the project from the 600,000 issues of Talk Magazine to a more mainstream ad campaign.
The lawsuit marks the latest protest against the company's latest campaign, which has triggered reaction from law enforcement officials and families of murdered victims.
The campaign associated with Benetton features one man who killed 13 people, another who slit an 84-year-old woman's throat, and yet another who bludgeoned three people to death and killed a 3-year-old.
"It's about capital punishment and Benetton decided to talk about it," Benetton U.S.A. spokesman Mark Major said. "It's an issue that's important to the company. We're a socially conscious company and don't mind having our brand attributed to it."
Cindy Finley, whose son was murdered by one of the prisoners featured in Benetton's controversial campaign, said she was completely outraged.
"This is an unfair campaign," Finley said. "I would like to see representation of our children and their hopes and their dreams, and I think it's just a big advertising gimmick, and I'm very outrged at it."
"We're showing these inmates with interviews in a unique way so you can sort of maybe get a feeling of what it's like to be on death row," Major explains. "I don't know many who would look at these ads and think these men are being glorified or glamorous."
Over the course of the past decade, the Benetton clothing company has built a reputation for shock advertising and has worn the controversy it's generated as a badge of honor.
Previous campaigns have shocked the Catholic Church, sparked outrage from veteran and human rights groups and offended activists in the AIDS community.