A man has been arrested and charged after allegedly robbing a Greymouth petrol station with a samurai sword.
Police earlier said the offender allegedly wielded a samurai sword during the robbery about 3.15am on July 8.
He allegedly took cash from the register before fleeing along Tainui Rd on foot.
No one was injured in the robbery but the station attendant was shaken, police said.
Police described the sword as silver with a black sheath and about 50cm long.