IOWA CITY, Iowa -- Former middleweight champion Michael Nunn was charged Wednesday with possession of cocaine with intent to deliver, federal prosecutors said.

Nunn, 39, was arrested Tuesday night after allegedly buying $24,000 worth of cocaine from an undercover FBI agent, said Al Overbaugh, spokesman for the U.S. Attorney's office. The charge carries a minimum sentence of five years in prison.

Chief U.S. District Judge Ronald Longstaff set a detention hearing for Aug. 9.

Nunn, a former IBF middleweight and WBA super middleweight champion, is being held by at the Muscatine County Jail without bail, Overbaugh said.

Nunn was represented in court Wednesday by attorney David Treimer. The court has yet to appoint an attorney for Nunn, and Treimer declined to comment on the case.

An affidavit filed in federal court said Nunn was arrested in the hallway of a Davenport hotel, moments after leaving a room with a kilogram of cocaine stuffed in his pants.

The arrest followed a July 26 meeting between Nunn, another man and an undercover agent, according to the affidavit. Authorities say Nunn agreed while driving around in the agent's vehicle to buy the drugs for $24,000 and pay an extra $1,000 in "tax'' for bringing the drugs across state lines.

The agent told Nunn he would have to pay the tax to obtain the drugs, and the three men also discussed delivering Nunn larger quantities in the future, according to the affidavit.

The other man who was with Nunn during the buy also was taken into custody Tuesday. Overbaugh declined to characterize the man's role in the case, but said he has not been charged and was released.

The arrest comes as Nunn was attempting to resurrect his boxing career. In September 2001, the Davenport native announced his intentions to make a comeback after a 22-month layoff.

In January, Nunn earned a unanimous decision over journeyman Vinson Durham in a 10-round cruiserweight bout in Indiana, his fourth consecutive victory.

In 1988, Nunn beat Frank Tate to win the IBF middleweight title. He defended his crown six times, but never achieved the status of legendary fighters of the time like Sugar Ray Leonard, Marvin Hagler and Thomas Hearns.

Nunn lost his title in 1991 to James Toney, who beat Nunn in the 11th round before more than 10,000 fans in Davenport.

He moved up a weight class and won the WBA super middleweight crown in 1992, defending the title four times before being upset in 1994.

But his professional success has been marred by legal troubles outside the ring.

Most recently, Nunn was charged in November with driving with a suspended license, assaulting an officer and interfering with official acts.

He has also been charged with various offenses since 1983, including drug possession, traffic violations and unlawful use of weapons, according to court records.