A South Carolina sheriff Leon Lott said Monday he was not going to charge swimmer Michael Phelps after a photo smoking from marijuana pipe.

The Associated press reports, Lott said during a news conference that he didn't have enough physical evidence to charge the swimmer, but he defended his investigation.

Michael Phelps is truly an American hero ... but even with his star status, he is still obligated to obey the laws of our state, Lott said.

USA Swimming suspended Phelps for three months in the wake of the photo, and Kellogg Co. said it would not renew its endorsement deal with him.