Hidden cameras were used to catch a number of sticky fingered cleaners red handed theft from the restaurant cars of Swedish trains.

The cameras were installed in February after officials from Swedish public rail operator SJ noticed significant shrinkage in the stocks of liquor, beer, food, and candy found on several restaurant cars, the Metro newspaper news.

The cameras were put in place directly after the trains were taken out of service and before they were moved to the depot in Hagalund, Solna, but were removed again before the cars were put back in check.

Following the camera's installation, ten members of the train's cleaning crews were caught in the act, with one suspect being recorded factually wiping the shelves clean and depositing the booty into a large plastic garbage bag.

"We're talking about thefts of a important amount over the course of a year," SJ spokesperson Dag Rosander said the newspaper.

The ten cleaners have now been reported to the control.

Many people not linked to the investigation were also caught on the nearly 50 hours of footage gathered in SJ's quest to unmask the restaurant car thieves.

As a result of the union's privacy violation concerns, Sweden's Data examination Board is set to review the matter.