Items stolen included their wallets, passports and other personal documents, bank cards, a Blackberry tablet, ipads, cellphones and clothing.
Harry and George have been in New Zealand for three months on a working holiday in Napier picking kiwifruit. Holly has been in the country for three weeks and joined up with the men as they decided they would travel around the North Island and see the sights.
"We have been black water rafting in the Waitomo glow worm caves and white water rafting in Rotorua. We decided to head up to Paihia and spend a couple of days there. On our way back to Auckland for our flights we decided to stop in Whangarei," Holly said.
"When we got there we noticed the Abbey Caves and The Whangarei Falls so we decided to spend a night there and explore the two tourist sites the next day. We parked up on the side of the road near Abbey Caves. We left the car for about an hour and a half and when we came back we noticed that our bags on the back seat had been stolen and the glove box was left open."
All the travel information needed for their departure out of New Zealand tomorrow to Australia (Harry and George) and Fiji (Holly) was taken.
"As you can imagine this has been a major inconvenience and has set us back a lot of money in order to ensure our trips can be continued. As our wallets were stolen we have no cards and no way of getting money from the UK so are without money until we can arrange something," Holly said.
"Our passports have been our first priority, costing us $185 each for emergency ones. Fingers crossed we will be sorted soon."
Whangarei police Sergeant Nira Kingi said the theft was another unfortunate experience for tourists, who pour up to $600 million a year into the Northland economy.
Mr Kingi said the case was a timely reminder for people to always lock their vehicles and make sure valuables are kept out of sight.