AMES, Iowa (AP) -

A federal lawsuit says Iowa State officials wrongfully barred a pro-marijuana group from using the school's Cy logo on T-shirts that also were decorated with cannabis leaves.

The Des Moines Register says the lawsuit alleges that the school violated two students' constitutional rights by barring use of the logo by the campus chapter of the National Organization for the Reform of Marijuana Laws.

The two students are Paul Gerlich, who is president of the chapter, and Erin Furleigh, who is vice president.

In 2012 ISU officials barred the group from using the Cy log after the chapter's president at the time displayed the T-shirt in a Register photo. The photo prompted lawmakers' complaints that the shirt made it look like the school endorsed pro-marijuana legalization.