ATLANTA (Reuters) - A semi-retired federal judge was sentenced on Friday to 30 days in prison for helping an exotic dancer buy illegal drugs, telling her "I'll watch your back any time."

Jack Camp, 67, pleaded guilty in November to charges of aiding a felon's possession of cocaine, marijuana and prescription pain killers. He admitted to illegal drug possession and to unlawfully giving his court-issued laptop to the dancer for her personal use.

"He has denigrated the federal judiciary, he has encouraged disrespect for the rule of law," U.S. District Judge Thomas Hogan said at Camp's sentencing hearing.

Camp was appointed to the federal bench in 1987 by then-President Ronald Reagan. He served as chief judge in the Northern District of Georgia before adopting senior status in 2008, a form of semi-retirement.

He resigned as part of his guilty plea.

Camp met the exotic dancer at an Atlanta club last spring when he paid her for a private dance, according to court documents.

In October, Camp and the dancer, who was then cooperating with authorities, purchased drugs from an undercover agent. Before the drug buy, Camp boasted that he was carrying a gun.

"I'll watch your back any time," he told the dancer, according to the documents.

Camp was arrested and two loaded pistols were recovered from his truck.

Camp called his behavior "wrong and foolish" and said he could not explain why he broke the law. "I am embarrassed and humiliated," he told Hogan.

Camp's wife, Elizabeth, wrote a letter to the court blaming her husband's behavior on bipolar disorder and to head injuries he suffered in a bicycle accident.

"I am steadfast in my belief that the crisis has to do with an internal war waged of the mind," Elizabeth Camp wrote.

(Reporting by David Beasley; Editing by Andrew Stern)