Atlanta: Federal agents arrested Grammy Award-winning US rapper T.I. on Saturday on charges of buying illegal machine guns, hours before he was due to star at a major hip hop awards ceremony.

Agents from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) said they arrested the rapper in Atlanta as he took delivery of three machine guns and two silencers.

"This convicted felon allegedly was trying to add several machine guns to an already large and entirely illegal arsenal of guns," David E. Nahmias, US Attorney for the Northern District of Georgia, said in a statement.

"Thanks to the good and quick work of ATF, he is now in custody and his firearms have been seized," Nahmias said.

T.I. was convicted of a violation of the Georgia Controlled Substances Act in 1998 and given seven years probation, the Department of Justice said.

It is a federal offense for a convicted felon to have someone else purchase firearms on their behalf, Justice said.

T.I., born Clifford Harris, was arrested at 2.30 p.m., the day he was due to perform at the BET Networks awards ceremony in Atlanta.

He had been nominated for nine awards at the annual show -- more than any other artist. They included the prestigious MVP award for the best artist in the business as well as best CD of the year and best lyricist of the year.

His failure to appear overshadowed one of the biggest events on the hip hop calendar and disappointed hundreds of fans who turned up to watch the elite of the hip hop industry.