American jurors and US anti-doping officials should decide Lance Armstrong's fate rather than the International Cycling Union, the main investigator who has chased Armstrong for years has said.

US Anti-Doping Agency (USADA) chief executive Travis Tygart spoke to the CBS television network in an interview broadcast on Sunday, saying he thinks the US Justice Department should join a fraud case against Armstrong.

Tygart also wants Armstrong to testify before the USADA rather than the world cycling governing body UCI, saying USADA-gathered evidence contradicts Armstrong's claims that UCI never assisted him in covering up a positive test.