Suspended Phillies reliever J.C. Romero has filed suit against a nutritional supplement manufacturer alleging an unlisted ingredient in one of its products caused him to test positive for a substance banned by Major League Baseball.

Romero, suspended for the first 50 games of the 2009 season, says he tested positive for steroids last August because a supplement he was taking, 6-OXO Extreme, did not specify it included androstenedione, a banned substance.

He filed suit Monday in Camden County, N.J. seeking punitive and compensatory damages.

Romero also named as defendants the corporate owners of two nutritional stores where he purchased 6-OXO Extreme, alleging sales clerks assured him it would not cause a positive test for a banned substance.