A former member of Toronto's police drug squad who refused to testify against his colleagues says discipline charges against him should be thrown out.

Jerry Cieslik worked on the same drug team as six other officers who are now the subject of the biggest police corruption prosecution in Canadian history.

Cieslik was told he was only a witness and was ordered to give a sworn statement to internal investigators.

He refused to talk and invoked his right to remain silent, claiming investigators were trying to get him to turn against his team.

Const. Cieslik was present the night his team arrested Chris Quigley, who is suing police, claiming some officers beat and robbed him.

Cieslik is neither named in Quigley's lawsuit, nor has he been charged criminally.

Police prosecutor George Cowley told a discipline hearing on Monday that Cieslik was quickly ruled out as a suspect and that he was instead a witness, under orders to talk about what he saw that night.

Cieslik's lawyer Andy McKay alleges investigators were trying to use the young constable because they saw him as the weakest member of the team.

"They flipped him into a witness officer status because they had nothing else," says McKay.

Caught between the brass and his colleagues, Cieslik is claiming abuse of process, and wants his discipline charges thrown out.