A NSW man might be about to wipe out his mortgage in one fell swoop, if a sensational claim he made about finding millions of dollars in cash and gold bullion in the wall of his newly-purchased house is true.

Speaking to Merrick Watts on Triple M earlier this week, "Dave" told the ebullient radio host he had uncovered the mother lode while renovating.

"Between the walls there are is bunch of money," Dave said. "Stacks and stacks of money – and gold bars."

"Have you counted the currency?" Watts asked.

"Yes I have," Dave said. "Between one to three million dollars."

"Jackpot!" Watts cried.

"There are about 50 gold bars, I estimate about half a kilo each," Dave continued. "And lots and lots of money here."

Jackpot? One of Merrick Watts's listeners claims to have found millions in cash and gold bullion in the wall of his house. (merrickwatts.com.au)

Dave, who confessed he hadn't even told his wife about the find, claims he reported the fortune to police about eight days before he called into the show.

Watts, for his part, told ninemsn that he has no doubt whatsoever that Dave is for real.

"One hundred percent," Watts said.

"I don't think for a second (that he's putting it on). I've worked in radio long enough, you can hear honesty through somebody's voice and you can just tell when somebody's pulling your leg. This guy's not. He's definitely found a huge, vast treasure trove.

"If anything, the only thing I think he may be incorrect about is the value of it. We've got a feeling that he may have potentially have found a larger payload than he thinks."

If Dave's story is not merely a mischievous canard – Watts told ninemsn he'd send the man a slab if it is indeed a hoax – two burning questions spring forth: where did the treasure (assuming it's not counterfeit)come from, and will Dave get to keep it?

Some of the Perth Mint's produce. (AAP)

There are only a few gold heists in Australian history that remotely fit Dave's description of the gold ingots, of which he says there are about 50, each weighing around 500g. The closest match for unrecovered bullion is the Perth Mint Swindle of 1982, in which 49 bars were "liberated" from the WA foundry.

Where do you think Dave's gold may have come from? Email newsproducers@ninemsn.com.au with your theory.

But Watts said yesterday on Merrick and Australia that Dave doesn't seem to think the treasure is ill-gotten, and the veteran broadcaster would himself prefer to think of it as ownerless "pirate gold".

Whichever way it turns out, if the story is true Dave will have to wait and see whether or not the riches will be his.

According to Melbourne barrister Peter Morrisey, Dave has done the right thing so far.

"When you find something that doesn't mean that it's been abandoned. If it's been abandoned, then you can keep it…but if it's just lost, well it's really got a different owner, like you or me if we left our wallet on the street," Mr Morrisey told Triple M yesterday .

"If they take it for themselves they've got an obligation to make reasonable efforts to find the true owner.