(Reuters) – A key witness in the Jerry Sandusky child sex abuse scandal sued Pennsylvania State University on Tuesday for more than $8 million on whistleblower, defamation and misrepresentation grounds.

Mike McQueary, a former Penn State assistant football coach, claimed in the suit filed in Centre County Court that he lost his job, was misled and publicly scorned because he had told about one of the attacks.

Sandusky, a retired Penn State football defensive coordinator, was convicted in June on 45 counts of child molestation in a case that riveted national attention on child sexual abuse. Sentencing is set for Oct. 9.

McQueary testified that he saw Sandusky raping a boy in a football locker room in 2001. He told jurors he then told head coach Joe Paterno, Athletic Director Tim Curley and university Vice President Gary Schultz about the incident.

The assault was never reported to police or child welfare officials. McQueary testified about it before a grand jury and Schultz and Curley were charged with perjury and failure to report suspected abuse.

McQueary, a former Penn State quarterback, was placed on administrative leave shortly after Sandusky, Curley and Schultz were charged in November 2011. He later lost his $140,000-a-year job as receivers coach.

McQueary is seeking at least $4 million in damages for alleged defamation arising from then-President Graham Spanier’s public support of Schultz and Curley after the charges against them were announced.

He is asking for at least $4 million for misrepresentation because Schultz, who headed the university police, and Curley allegedly told him that appropriate action would be taken over the locker room incident.

The former coach alleges he lost his job because he cooperated with law enforcement and will be a witness in Curley and Schultz’s trial. He is in part seeking reinstatement to his job or payment of lost wages.

A university spokesman said the school would have no comment.

Penn State is facing lawsuits from at least three of Sandusky’s victims. It said last month it wanted to try to settle suits by the end of the year.

Trustees fired Paterno and Spanier shortly after the charges against Sandusky, Schultz and Curley were filed. (Reporting by Ian Simpson; Editing by Jackie Frank and Todd Eastham)