DES PLAINES, Ill. (CBS) – A former deputy police chief for Des Plaines, who claims he was fired after he blew the whistle on police brutality, has filed a federal lawsuit against the city.

The lawsuit talks about half a dozen incidents of brutality – allegedly involving former Des Plaines Police Officer John Bueno.

According to the lawsuit, former Deputy Chief of Investigations Richard Rozkuszka started hearing about Officer Bueno in 2009. Rozkuszka claims he investigated brutality allegations against the officer.

LISTEN: WBBM Newsradio’s Steve Miller reports

“And we found out that John had taken this offender, Joseph Perez, out of a cell and began to beat him up,” Rozkuszka said. He claims he told the police chief what he found out, but nothing was done against Bueno.

“I personally believe he was afraid of being sued,” he said.

Rozkuszka said he thinks, if Bueno had been fired or disciplined, that would have opened up the Des Plaines Police Department to lawsuits from people they’d arrested.

Rozkuszka claimed he was fired because he went to Cook County authorities, and now he wants compensation and his reputation back.

Bueno was fired earlier this year. He has filed a racial discrimination suit against the city of Des Plaines.

WBBM Newsradio has tried to reach the City of Des Plaines for comment. Efforts to reach former Police Chief James Prandini, who is also named as a defendant, have not been successful.