More than 6,600 police officers were dispatched to a tiny Japanese island as the authorities faced growing embarrassment over their failure to track down a missing prisoner behind a spate of petty robberies.

Described as a “model inmate”, 27-year-old Tatsuma Hirao walked out of an open prison on the 8.5-square mile Mukaishima island near Hiroshima on April 8 and has evaded all attempts to recapture him since - prompting an apology from Japan's justice minister.

Police believe he is still on the island as a number of houses have been broken into and food, cash, a mobile phone, sandals are missing, according to Japanese media who have swarmed to cover the bizarre manhunt in a country that enjoys one of the lowest crime rates in the developed world.

Reports also suggested that Hirao had stolen a car. But in another odd turn had reassured the owner that he would take good care of the vehicle, leaving a note saying: “I am borrowing your car but I will not damage it."

The authorities drafted in thousands of officers from forces close to Mukaishima, in Hiroshima Prefecture, and are searching cars and abandoned buildings across what is normally a peaceful island, which is heavily forested and hilly.