Thieves who dressed up as police officers to con victims out of nearly 160 kilogrammes of gold worth $7 million were handed lengthy prison sentences on Monday.

In 2016, the three fake cops stopped a group of men carrying briefcases with gold bars worth 750 million yen in the southern city of Fukuoka and ordered them to hand them over, telling them they knew the gold had been smuggled.

Apparently taken in by the disguise, the victims gave the pretend police what they asked for and simply watched as they drove off.

On Monday, the Fukuoka district court ordered "a seven-year jail term for 36-year-old Tomonori Shiraishi and 5.5 years in prison for Takahiro Shirane, 28, and Takumi Uchida, 26", a court spokesman told AFP.

The heist happened as the men were on their way to sell the 160 kilogrammes of gold. The men who were robbed later told the real police they had bought the metal the day before.

Initially police said the haul was worth 600 million yen, but it later transpired the gold had a value of 750 million yen, according to local media. 

In 2017, three masked robbers in Fukuoka snatched a suitcase stuffed with 380 million yen in cash from a businessman who had just withdrawn the money from a bank to purchase gold bars.