A cleaner called police to report the package left on top of a waste bin on Saturday. Part of the station, known for its stained-glass ceiling, was cordoned off and explosives experts were called in.

TV pictures showed a police officer in a full protective suit entering the toilet carrying specialist equipment while other officers waited outside with more gear.

The officer then emerged carrying a bright blue cardboard box full of mooncakes, pastries with sweet fillings traditionally eaten at the Mid-Autumn Festival.

“It was X-rayed first to see what it was and whether there was any chemical or electrical reaction,” local police station chief Cheng Ming-chung told TV.

“Someone must have put it down to use the toilet and forgotten it when they left,” he said, adding that the police would continue to investigate.