Gold bars worth ¥600 million ($5 million) were stolen by men disguised as police officers in the city of Fukuoka sometime around spring this year, investigative sources said Wednesday.
According to the sources, a group of men on the way to a cash-for-gold store was approached by the fake police officers near JR Hakata Station.
The men were carrying briefcases containing more than 100 kg of gold bars, which the fake police officers took before escaping by car.
The men explained to police that they had been making money by reselling precious metals. They also said they had purchased the gold bars the day before the incident.
Police suspect organized crime in the case because the thieves seemed to have prior knowledge that the gold bars were going to be sold.
Police also found the fake police officers' uniforms believed to have been used in the crime in neighboring Yamaguchi Prefecture.
According to the Finance Ministry, the number of unlawful gold import cases has been increasing amid a rise in gold prices. In the year from July 2015, customs authorities in Japan discovered a record-high 294 smuggling cases.