A GRAFTON police sergeant was in Prince St, Grafton about 7.45am yesterday when a member of the public asked him if he'd be interested to know that there was a man with a knife at Coles around the corner in King St.
The officer leapt to action, called for assistance and headed to Grafton Mall where a staff member directed him to a Ford Falcon parked in King St outside Centrelink.
A member of the NSW police dog squad responded to the call as did Grafton general duties officers and detectives.
Police said a 19-year-old Muswellbrook man was arrested and later charged with intimidation and knife-possession charges.
Police recovered a medium-sized plastic-handled fishing knife.
Another man and a woman were also arrested but the man was later released without charge and the female was issued a criminal infringement notice for offensive language.
It is understood several witnesses contacted police independently about a man with a knife and that the trio had been asking passers-by for cigarettes yesterday and the day before in Grafton streets.
Police will allege the 19-year-old man showed the knife to a supermarket staff member on his way through the checkout.
Grafton police would like to speak to the man who alerted the officer in Prince St.
A Coles Supermarkets spokes- person confirmed that no staff members were injured in the incident but declined to comment further.