An ex-police officer who admitted misusing his force's helicopter to film people having sex hid his "swinging and voyeurism", a court has heard.
Adrian Pogmore, 51, used the aircraft to film people sunbathing naked and a couple, who were his friends, having sex in their garden.
Four other men all deny charges of misconduct in a public office.
Giving evidence at Sheffield Crown Court, a former colleague said he did not know Pogmore was "into voyeurism".
Police officers Matthew Lucas, 42, and Lee Walls, 47, and helicopter pilots Matthew Loosemore, 45, and Malcolm Reeves, 64, are all on trial.
Pogmore made four recordings from the aircraft between 2007 and 2012, including filming two naturists sitting outside a caravan on a campsite and his friends having sex, the court heard.
The jury was told he knew the couple because they "shared his sexual interest in the swinging scene" and the pair had "brazenly put on a show" for the helicopter.
When asked by Mr Loosemore's defence barrister, Neil Fitzgibbon, if he believed it was appropriate for someone "into swinging and voyeurism" to operate a £1.5m police helicopter camera, ex-colleague PC Tim Smales replied: "certainly not".
PC Smales agreed with Mr Fitzgibbon when asked: "It would be fair to say Mr Pogmore kept his swinging and/or voyeurism a secret?"
He replied: "Certainly from me, yes."
The officer told the jury he would have reported it if he knew Pogmore was "into voyeurism and swinging" and that he worked with him for a number of years before Pogmore was dismissed from South Yorkshire Police.
Prosecutors had described Pogmore as "a swinging and sex-obsessed air observer", while the jury was told the other four men blamed him for the recordings.
The court heard how the footage was found among Pogmore's property at a police station, and he was the only defendant present during all four incidents.
Pogmore, of Guilthwaite Crescent, Whiston, Rotherham, has admitted four charges of misconduct in a public office.
Mr Reeves, of Farfield Avenue, Knaresborough, North Yorkshire, denies two counts of the same charge.
Mr Walls, of Southlands Way, Aston, Sheffield, denies one count.
Mr Loosemore, of Briar Close, Auckley, Doncaster, denies one count.
Mr Lucas, of Coppice Rise, Chapeltown, Sheffield, denies three counts.
The trial continues.