However, police who responded to phone calls about the man, later confirmed he did not pose a threat to the public.
The man, believed to be in his 60s, was spotted walking on to the beach by two local residents driving towards Avarua. They immediately phoned the police.
However, the rifle turned out to be a licensed pellet gun, which the man told police he intended to use to scare chickens away from the area.
Cook Islands Police spokesperson Trevor Pitt said the first call informing them of the armed man was logged at 8.28am. He said police officers responded to the call in minutes.
“Police treated the call as high priority. The person (carrying the gun) was missed as he had just left (when police arrived at the scene). Calls from the public started coming in to headquarters at 8.42am,” Pitt said.
“Police treated it as serious, dispatching four very senior officers in two vehicles.
“Two people were subsequently located for questioning at police headquarters yesterday.”
At around 11am, police posted an item on their Facebook page assuring the public that the report of an armed man sighted at Nikao during the morning had turned out to not be a threat.
“Police have attended to the matter and there is no cause for alarm. Police are contacting the person sighted,” the post read.
Pitt said police spoke to the man about his behaviour. However, they did not divulge any further information about their interview with him apart from noting that the conditions of the man’s gun licence contained “certain rules”.