Douglas County District Attorney David McDade has said he was required by the state's open records law to release the tape because it was used as evidence in the trial against Genarlow Wilson, who was 17 when it was made.
U.S. Attorney David Nahmias said the tape "constitutes child pornography under federal law" and should not be distributed to the public.
"These laws are intended to protect the children depicted in such images from the ongoing victimization of having their sexual activity viewed by others," he said. Mr. Nahmias urged people with the tape to destroy or return it.
The video shows a 2003 New Year's Eve party at a hotel room. On it, Mr. Wilson can be seen receiving oral sex from a 15-year-old girl and having intercourse with a 17-year-old girl.
Although the sex act with the 15-year-old was consensual, it was a felony under Georgia law at the time, and he was given a mandatory sentence on a charge of aggravated child molestation. Mr. Wilson was acquitted of raping the 17-year-old.
Last month a Monroe County judge declared Mr. Wilson's sentence a "grave miscarriage of justice" and ordered him released. The state Supreme Court is set to hear a pair of appeals from Mr. Wilson next week.
Mr. McDade has said his office gave copies of the tape to 35 parties who requested it.
On Tuesday, State Sen. Emanuel Jones, a Democrat, asked Attorney General Thurbert Baker to investigate the tape distribution.
Mr. Nahmias would not confirm whether his office is investigating the matter.