Two council workers used CCTV cameras to spy on a woman as she undressed for a bath, a court has heard.
The men were themselves caught on a camera monitoring Sefton Council's CCTV control room, a jury at Liverpool Crown Court was told.
Kevin Judge, 42, of Crosby, Merseyside, and David Welsh, 40, of Anfield, Liverpool deny charges of voyeurism.
Mr Judge and Mr Welsh were recorded playing back the video of the woman, the court heard.
Mr Welsh denies a second charge of misconduct in public office.
Two other men have admitted offences relating to the investigation.
One man has admitted voyeurism and another misconduct in public office.
Peter Davies, prosecuting, said "These cameras were misused. Instead of focusing on streets and car parks they focused on a young lady inside her own flat, where she was in the bath, where she was undressing, where she was going to the toilet.
"The cameras were focused and manipulated on her while she was believing she was enjoying her privacy."
Mr Davies said the cameras first focused on the woman as she greeted her boyfriend and spoke with him in the front room.
After the man left, the woman ran a bath and walked around the flat undressing.
The images, which were automatically recorded on a computer hard drive, captured full nudity, as well as the woman in her underwear.
Mr Davies said the camera monitoring the CCTV control room showed Judge turning down the lights as the film was shown on a large screen.
He added: "Mr Welsh is seen to be in an avid and animated mood. He is seen to point to the screen and raise his hands to his eyes in a gesture to suggest binoculars."
The trial is expected to last a week.