A former Ernst & Young manager was sentenced to four years in jail Monday for what British authorities are calling the largest case of voyeurism they have ever seen.

George Thomas, 38, secretly filmed more than 3,500 people in public places over a six-year period beginning in 2009, a judge said, according to The Telegraph.

Thomas installed cameras and recording devices in bedrooms and bathrooms in his own home, in shower rooms and bathrooms at work and in coffee shops around London, with the goal of filming naked bodies and genitals. Prosecutors said even some children and babies were recorded, with the footage stored on his computer at work. Thomas is a married father of one.

“This case is undoubtedly a sophisticated, organized, planned and long-running campaign of voyeurism the scale of which, the court has been told, is beyond any previously encountered by the Metropolitan Police,” Judge Jeremy Donne said.

In a few instances, Thomas matched images of victims in public areas with covert bathroom recordings, making compilation videos for his own “sexual gratification,” The Telegraph reports.

He was busted in March when a female colleague found a device in the gym showers at his workplace. Thomas’ face was caught on camera hiding one of the devices.

Police also found two covert cameras and a number of memory cards in his gym locker.

“These criminal charges concern a disturbing invasion of individual privacy which we find appalling,” a spokesperson from Ernst & Young told The Telegraph. “We have been doing everything we can to support those individuals from EY affected and to assist the police in their ongoing investigation. The individual has now been convicted and sentenced."

Thomas pleaded guilty to 15 offenses, including acts of voyeurism and making indecent images of children.

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