The lawyer, Nick Kaufman, was hired last year by the late dictator's daughter, Aisha. Kaufman has represented other controversial figures in the past on the grounds that everybody deserves a fair trial.
Gadhafi's son Seif al-Islam was captured a month after his father's death on Oct. 20, 2011, and is being held in Libya.
The International Criminal Court has not approved yet the new Libyan government's plans to try Seif al-Islam in Libya for crimes against humanity.
Libya wants to try him at home.
Kaufman accused Libya of being incapable of giving Gadhafi's son a fair trial. He spoke Friday to The Associated Press.