The Iga-ryu Ninja museum, dedicated to the history and practices of ninja, suffered the break-in on Monday morning.

There were no staff at the museum at the time, but the thieves set off an alarm which alerted the police who arrived to find the entrance had been forced open and a safe was missing.

The safe, reportedly weighing around 150 kilograms, contained admission fees to the value of over a million yen (around €8,000 or £7,200).

An official at the museum told CNN: “It was a three-minute job. It was planned, they must have scoped us out and singled us out.”

Security footage recorded a car pulling up to the building and a man climbing out of the passenger seat. He then titled the security camera down so it only filmed the ground for the rest of the night.