Monsanto Co., the world’s largest seed company, may face more complaints from farmers even as tests so far haven’t shown unapproved gene-altered wheat anywhere beyond an Oregon farm where it was found.

The company was sued in federal court in Wichita by a Kansas farmer who accused it of negligently releasing genetically altered wheat seed in the U.S. and damaging the market for his crop. The lawsuit filed June 3 by Ernest Barnes of Morton County, Kan., may be the first of many against St. Louis-based Monsanto alleging contamination, his lawyers said in a statement.