Feb. 17 (Bloomberg) -- Olympic swimmer Michael Phelps won’t face legal prosecution after being photographed smoking from a bong at a college party and getting a three-month swimming ban.

Sheriff Leon Lott of Richland County, South Carolina, said there wasn’t enough evidence to charge Phelps, who won a record eight gold medals in Beijing in 2008. A photograph taken at a South Carolina college party in November showed Phelps inhaling from a water pipe, which is commonly used to smoke marijuana.

“We had a photo and him saying he was sorry for inappropriate behavior,” Lott said during a televised press conference. “He never said, ‘I smoked marijuana.’ We didn’t have physical evidence.”

The 23-year-old Phelps, who apologized for his conduct the day after the photo was published Feb. 1 in London’s News of the World, said last night that he’s glad the matter has been “put to rest” and that he’s anxious to return to swimming.

“For me, it’s all about recognizing that I used bad judgment and it’s a mistake I won’t make again,” he said in a statement through his representatives, Octagon. “One bad decision can really hurt you and the people you care about.”

Lott said he hoped children would learn that no matter who you are, you can’t break the law.

Star Status

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

Phelps, who has won a record 14 Olympic gold medals, said Feb. 2 that he “acted in a youthful and inappropriate way” and not in a manner that people had come to expect from him. He has said the picture is authentic.

“For this, I am sorry,” Phelps said. “I promise my fans and the public -- it will not happen again.”

USA Swimming banned Phelps from competition for three months on Feb. 6, though he didn’t violate any anti-doping rule. Kellogg Co., the world’s biggest cereal maker, said it wouldn’t seek to renew a sponsorship agreement with Phelps that concludes at the end of this month.

The majority of Phelps’s sponsors, including Speedo International Ltd., Mazda Motor Corp. and Swatch Group AG’s Omega brand, have said they are sticking with the most successful Olympian in history.

Phelps, who has never failed a drug test, also ran into trouble over substance abuse after the 2004 Olympics. After winning six gold medals at Athens, he was charged with under-age drinking following a traffic stop in Maryland and was sentenced to 18 months of probation.

To contact the reporter on this story: Mason Levinson in New York at mlevinson@bloomberg.net.

Last Updated: February 17, 2009 00:01 EST