Police are yet to make any arrests for the armed robbery at Westport's Mill House Dairy on Sunday night.
Sergeant Malcolm Lamont said they were talking to a number of people and examining CCTV footage for evidence.
Three men armed with a gun held up a 17-year-old living at premises attached to the dairy late Sunday night and beat him.
The intruders stole cigarettes, tobacco, computers and other items before making off in the victim's car. The car was later found alight near the bottom of Alma Road.
Mr Lamont said the victim's brother was first on the scene of the burning car and managed to put the fire out with a fire extinguisher.
Damage was limited to the seat where the fire was set so it was examined for forensic evidence yesterday.
Greymouth CIB was prioritising the forensic tests and results should be known today or tomorrow, said Mr Lamont.
The total value of goods stolen would not be known until a full inventory was taken in the dairy today, he said.
Anyone with any information about the robbery or the stock that was taken should contact Westport police on 789 7339, Detective Sergeant Kirsten Norton on 021 191 5738 or Crimestoppers, anonymously, on 0800 555 111.
Mill Street Dairy reopened today after being closed all day yesterday.
The dairy owner, who preferred not to be named, said the robbery affected everybody. He was dealing with staff worries and family worries today. His son was alright physically but having to deal with what had happened to him.
The owner praised the police for their response and said there had been great support from the community which was ongoing.
The business had insurance cover for a forced closure but this only covered costs, he said.
- Westport News