"Lance Armstrong was living in his own horrible world," Cooke told BBC Radio Five Live. "He's got no morals and he's a disgusting human being. He admitted to taking drugs but he hasn't totally uncovered what was going on and he didn't want to get into naming names.
"There's still also the question of how deep was that corruption that surrounded Lance Armstrong that supported him and enabled him to get through testing. There are still so many questions to be asked and answered."
Armstrong was issued with a lifetime ban after the United States Anti-Doping Agency accused the cyclist of taking performance-enhancing drugs.