Hong Kong media say police have arrested a man from mainland China on suspicion of robbing about 1 billion yen, or around 6.4 million dollars, from the staff of a currency exchange shop on Thursday.
Local media outlets say the police received the report from the shop in the Sheung Wan district.
Two staff members were reportedly carrying four suitcases containing cash that they were going to change for Hong Kong dollars at a nearby bank.
The shop reportedly told the police that three knife-wielding men threatened the staff and robbed them before fleeing by car.
Police say they arrested a 43-year-old man who was carrying a suitcase containing a large amount of Japanese yen.
They say they also found the suspected getaway car.
Police are searching for the other suspects.
