IOWA CITY, Iowa -- Lawyers are seeking class-action status for a lawsuit that claims Hall of Fame slugger George Brett has been falsely advertising necklaces and bracelets as being able to help improve health and sports performance.

A lawsuit filed Monday in federal court in Des Moines claims Spokane Valley, Wash.-based Brett Bros. Sports International Inc. has falsely claimed its Ionic Necklaces help customers relieve pain in the neck, shoulders and upper back, recover from sports fatigue and improve focus. The company has also falsely claimed its bracelets, which include two roller magnets, would relieve wrist, hand and elbow pain, the lawsuit said.

Brett, who was inducted to the Hall of Fame in 1999 after a 21-year career with the Kansas City Royals, has been president of the company since 2001 and appears in its advertisements.

The claims appeared on the company's website from 2008 to 2010, and still appear on the packaging of the products and on the websites of its distributors, according to the lawsuit.

"Most consumers, when reading these claims, and seeing the products endorsed by a high-profile baseball player, assume that these products have the health benefits that are marketed and advertised and that scientifically significant research supports statements made by Brett Bros., when in fact that is not the case," reads the lawsuit, which alleges the company has violated the state Consumer Frauds Act and been unjustly enriched.

The lawsuit says an Iowa man, Seth Thompson of Adel, bought one of the necklaces for $30 at the College World Series in Omaha last year after reading Brett's endorsement of them. He hoped the product would reduce stress and fatigue and boost his energy and concentration, but none of those benefits were realized, rendering the product "useless to him," the lawsuit says.

His lawyers, who include Bart Goplerud of West Des Moines and two from firms in Los Angeles, are asking a federal judge to approve a class-action lawsuit on behalf of thousands of customers who have bought the products in the last four years. Total damages "are likely in the millions of dollars," the lawsuit says.

Brett declined comment Tuesday, saying his business partners and lawyers were still reviewing the case, the Kansas City Star reported.

"I haven't read it," Brett said, according to the Star. "They're going to finish reading it tonight and tomorrow. I'll talk to them then, and we'll figure out what our response will be."

Brett, 58, retired from baseball in 1993 after accumulating 3,154 hits and 317 home runs, winning three batting titles and making 13 All-Star teams.

Information from The Associated Press was used in this report.