Two police officers told a court they did not see their colleague assaulting people he was detaining.
Detective Constable Russell Gillespie is accused of a total of 11 charges of assaulting people in custody and breach of the peace, at various locations across Perth, Angus and Dundee, dating back to 2009.
Detective Sergeant Scott Fotheringham, 44, was involved in a surveillance operation of a drugs suspect on May 31 2011 in Lochee.
He said he was following a suspect, Jamie Duncan, who was in a taxi being driven by Maurice Fraser. He said he saw Gillespie going over to the taxi and went to assist him.
When he got there, Mr Fraser alleged he had been punched in the face, Dundee Sheriff Court was told.
Asked by depute fiscal Beverley Adam whether Mr Fraser had any injuries, he said he had looked for any sign of injury but he could not see anything.
DC Jamie Abel, 36, said he and Gillespie handcuffed suspect David Donald after a struggle in a Dundee police operation.
DC Abel told the court he did not see what Gillespie had done to help him get Donald under control.
