"Despite what the word 'trafficking' suggests," the official said, "it is not human smuggling ... [and] does not require proof of movement or crossing of borders."
Human trafficking is a federal offense because it violates the 13th Amendment, which prohibits slavery.
The Justice Department has conducted more than 700 investigations into cases of alleged human trafficking since 2001, an increase of 600 percent over the previous six years.
In 2006, the department initiated 168 investigations, charged 111 defendants in 32 cases, and obtained 98 convictions involving human trafficking cases.
In December 2007, Mahender and Varsha Sabhnani of Muttontown, N.Y., were found guilty of human trafficking by a federal court.
The Sabhnanis were accused of keeping two Indonesian women, identified only as Samirah, 51, and Enung, 47, as slaves in their Long Island home. Prosecutors accused the couple of forcing the women to work long hours without pay and physically abusing them.
They were convicted on 12 counts, including involuntary servitude, conspiracy, forced labor and harboring aliens.
The Sabhnanis could face up to 40 years in prison and are scheduled to be sentenced later this moth. Mahender remains free on $4.5 million bail, but Varsha had her bail revoked and awaits sentencing from jail.
No trial date has been set yet in the Georgia case.