Kimberlin was placed in solitary confinement in ‘88, on the same day he was to hold a press conference. He later charged prison officials with trying to silence him. Last year a federal judge found there was enough evidence of government wrongdoing for a trial. A hearing on a government appeal is set for October. Now NEWSWEEK has learned that Michigan Sen. Carl Levin is also investigating the incident. Levin requested written answers from the Justice Department to 33 questions about the handling of t case. If not satisfied with Justice’s response, Levin may hold hearings in September. Quayle has flatly denied the dope charge. Prison officials deny trying to muzzle Kimberlin.