Holidaymakers at a remote campground north of Westport awoke to find wads of cash had been left for them yesterday morning.
More than $6800 was anonymously left under windscreen wipers and at tent doors all around the Gentle Annie Seaside Accommodation and Camping Ground.
Owner Jesse Paley-Atkins believes the cash was doled out between midnight and 2am, because some campers heard noises around this time.
Most people found $200 to $300 on their car or tent.
"It seems an unknown person has distributed what turns out to be nearly $7000... in $50 and $100 denomination notes to all the cars in the campground, under the window wipers, and outside tent doors, and in the bathrooms of the camping grounds - pretty much anywhere campers would wake up to find it," Mr Paley-Atkins said.
"It's a complete mystery - there has been no note or indication from the person or people who have done it.
"It is a large area, so somebody has run around laboriously doing it with a sack... or had a couple of helpers."
Happy campers were thrilled with their morning windfalls.
"A lot of campers just came in asking us what was going on and perhaps thinking that we might have been giving them a Christmas present or something," Mr Paley-Atkins said.
"The campground was a bit of a buzz this morning as everyone woke up to find the money."
Although the gesture looks like extreme kindness, to be on the safe side Mr Paley-Atkins gathered all the money up and handed it to the police to decide.
He made a list of the campers who found money and hopes they will get it back soon.
"Perhaps it's a large act of generosity that's fairly unlikely these days - it's pretty heart-warming to be involved in," he said.
Among the first to encounter thousands of dollars of mystery money was Christchurch man Tim Hornblow, who is staying at the campground with friends from Switzerland.
He returned from an early-morning trip to the loo $550 richer.
"There was $200 spread across the handbasin and the floor of the bathroom and it turns out the friends I was staying with found the same in the ladies. As I was walking back I found $150 on the walkway and $250 on the car," he said.
"Initially I thought, oh cripes, someone's had a wad of cash in their pocket and it's spread all over the place."
When he walked to the campsite office to hand the money in later that morning, he found dozens of other campers queued up, each with two and three hundred dollars in hand.
"It was a bit surreal, really."
To be on the safe side, campsite owner Jesse Paley-Atkins has collected up the money and handed it into the police.
The police are now appealing for anyone in the Westport area to get in touch if they recently lost a significant sum of cash.
Mr Paley-Atkins has noted down who found money and if nobody comes foward it will be finders-keepers.
At this stage he said it definitely looks as if it was a random act of kindness.
"There's a few sideways glances in the campsite today, people smiling at each other and thinking you know, maybe they did it, because I guess one explanaiton could be that it was a camper in the campground just having a wee smile to themselves."
He said he'll remember Saturday as an amazing day.
"My family's had this campground for over 40 years and it's the most bizzare thing we've experienced, for sure."
If police do release the money, some campers have already decided what they'll spend it on.
The campground's Cafe manager, Benny Reckner is one of many keen to pay the generosity forward, by donating to a local Westport charity.
For Mr Hornblow, it will go a long way towards funding more trips to his favourite campground over summer.