T.I. was arrested Saturday — just hours before he was to take the stage at the BET Hip-Hop Awards — after federal officials said he had paid his bodyguard to buy machine guns and silencers for him.

The arrest resulted from an investigation that began this month when a federal firearms licensee contacted the Bureau of Alcohol, Tobacco, Firearms and Explosives about a man inquiring about buying a machine gun without registering the weapon as required by law, 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 Clifford Harris, T.I.’s given name, the complaint said. According to the bodyguard, he had bought about nine firearms for T.I., and the rapper had given him cash to buy guns four different times, it said.

Harris brokered the deals through the bodyguard because he 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 had arranged to pick up the weapons just hours before he was to take the stage at the Hip-Hop Awards, being taped blocks away, according to the complaint.