A junk food craving may end up costing a helicopter pilot $100,000, after he made an unauthorised landing on the island nation of Nauru to pick up some soft drink and chocolate.

Nauru government spokesman Rod Henshaw told Radio Australia's Pacific Beat program the pilot, based on board a Taiwanese fishing vessel, was arrested by police when he landed on the beach near the island's main supermarket.

"I heard last night that this chopper had landed at Capelle Beach, which is just in front of the main supermarket here on the island, and they apparently told the police that they saw the supermarket sign so they landed there and went and got some chocolates and some soft drinks and a few snacks," he said.

Mr Henshaw, a former ABC journalist, said the pilot told police he had been offshore for more than two months and was going "sea crazy".

"So apparently he gave the story to the police that he'd been 75 days at sea and he was going sea crazy, so he said 'look, we're only a short hop from this island, let's go and see what we can get in the way of a few snacks'," he said.

"So he and his passenger hopped aboard this little two-seater and away they went."

Unfortunately for the pilot, a 24-year-old Australian man, police were unmoved by their plight and impounded the helicopter.

"After they landed, that's when it aroused quite a bit of attention, particularly from the police, who then intervened," Mr Henshaw said.

"[The pilots] said 'well, we'll be off now thank you very much' and they [the police] said 'well, it's not quite that simple. We're detaining you and we're impounding your aircraft - let's fly it to the airport', which they did under onboard escort, and that's when the further questioning took place.

"It seems that they could be up for a maximum fine of $100,000 or the pilot could be for the unauthorised landing - that's against the Civil Aviation regulations - and also further action for breaches of the Immigration Act for entering in illegally, either entering without visas or the necessary documentation."

The pilot has since been released from custody.