Cyclone Oma stripped metres of sand from eastern Australian beaches when the system brushed past last month, but it also opened up new opportunities for bounty hunters looking for hidden treasure.

Amateur detectorist, Murray Beattie, said he took five days off his job as a painter to comb eroded beaches on Queensland's Gold Coast.

"It's uncovering a lot of material that's been sort of hidden for years under a lot of sand," he said.

"A lot of coins and jewellery and just things that have been there for a long time."

A selection of items found by amateur detectorist Murray Beattie after Cyclone Oma. ( Supplied: Murray Beattie )

The 36-year-old from Casuarina, in northern New South Wales, found $70 in coins and a collection of rings and jewellery.

He said most of it was worthless, but the thrill of the hunt was what drew him back to metal detecting after an earlier foray as a child.

"Just looking for treasure, you don't know what you're going to find," he said.

The lure of hidden loot has drawn dozens of people to beaches on the Gold and Sunshine Coasts.

There are laws in Queensland that require people who find valuable items including watches, mobile phones and jewellery to hand them in to police.

"If you don't hand it in you could be charged with stealing by finding," Senior Constable Tracey Clousten said.

"If that can be proven and you do end up with someone else's property, that you haven't handed in, then you can be charged for that."

Main Beach on the Gold Coast was among many heavily eroded across Queensland and NSW by Cyclone Oma. ( ABC Gold Coast: Tom Forbes )

Mr Beattie said he was happy to hand over valuables if the owners could be located.

"I've given a few rings back, bits of jewellery to people who have lost it," he said.

"A couple of wedding rings and older bits of jewellery that are special to people."

The detectorist has even started a community Facebook page where he offers to help people find lost valuables.

"This weekend I am going to see a lady who has lost an earring and hopefully find it for her," he said.

Territorial secrets

With the odds of finding treasure now increasing, the number of people looking for it has also risen and Mr Beattie said that could lead to territorial disputes.

"If you find a patch or a bit of turf that's quite productive you don't want to tell anyone else because you want it all for yourself," he said.

"I have heard of … a bit of competition, sometimes friendly competition."

Many detectorists venture to the beach at dusk or dawn to avoid the crowds or negative comments from people who deem them opportunists aiming to capitalise on other people's misfortunes or bad luck.

"Some are looking at you scratching their heads," Mr Beattie said.

"Most don't have an issue. Most are just curious. A lot of kids are curious, obviously. They chase you around."

The amateur treasure hunter has even bought his two-year-old son, Taj, a toy detector.

"He got it for Christmas and he loves it," Mr Beattie said.

"I don't think he really knows what it is yet, but he loves it."