Grammy-winning rapper T.I. was arrested Saturday — just hours before he was to perform at the BET Hip-Hop Awards — in a parking lot where federal officials said he planned to pick up machine guns and silencers his bodyguard bought for him.

T.I., born Clifford Harris, is charged with possession of unregistered machine guns and silencers, as well as possession of firearms by a convicted felon. Harris was in federal custody, said U.S. attorney's office spokesman Patrick Crosby, who would not disclose his location.

Sydney Margetson, a spokesman for T.I.'s label, Atlantic Records, declined to comment Saturday evening.

The arrest resulted from an investigation that began this month. A federal firearms dealer told the Bureau of Alcohol, Tobacco, Firearms and Explosives that a man was inquiring about buying a machine gun without registering the weapon as required, according to a criminal complaint filed Saturday in U.S. District Court in Atlanta.

After trying to buy several machine guns from an undercover ATF agent, the unnamed person began cooperating with the government and said he was buying the machine guns and silencers for Harris, the complaint said. The bodyguard said that he had bought about nine firearms for Harris, and that the rapper had given him cash to buy guns four times, the complaint said.

Harris brokered the deals through the bodyguard because the rapper is a convicted felon, the complaint alleged. It is against federal law for a convicted felon to have another person get firearms on their behalf.

The 27-year-old rapper arranged to meet with the bodyguard Saturday to exchange cash for weapons, the complaint said. After his arrest in the shopping center parking lot not far from the awards show, agents found three firearms in the vehicle he was driving, including a loaded firearm between the driver's seat and center console, according to the complaint.

As the awards were being taped in Atlanta on Saturday night, federal authorities were still searching T.I.'s home in East Point, about 15 miles southwest of the city.

Agents found six guns in a closet, including three allegedly bought by the bodyguard for the rapper last month, according to the complaint. Five were loaded, agents said.

T.I. had been expected to perform at the BET show, which is to be broadcast Wednesday, and was nominated in nine categories. Instead, the rapper was noticeably absent from red carpet festivities before the show began at 6 p.m.

The co-chief executive of Grand Hustle Records won three awards at last year's inaugural BET Hip-Hop Awards and received nine nominations this year, including CD of the Year, Lyricist of the Year and MVP of the Year. His sixth album, "T.I. vs. T.I.P.," was released July 3 and debuted at No. 1.

T.I. won two Grammys in 2006, including best rap/sung collaboration for "My Love" with Justin Timberlake. He also hit the big screen in "ATL" that year, and he has a role opposite Academy Award winners Denzel Washington and Russell Crowe in "American Gangster," set for release Nov. 2.

T.I. grew up in Atlanta and was selling crack by the time he was a teenager. In 2004, warrants were issued for his arrest on probation violations for a drug conviction, and he was sentenced to three years behind bars. It wasn't clear Saturday how much of the sentence he actually served.