Second-hand jewellery dealers and pawnbrokers should be banned from operating in licensed venues to protect problem gamblers from "predatory" behaviour, South Australia's Labor Opposition says.

Key points: Second-hand jewellery is being sold in some licensed venues around Adelaide

Second-hand jewellery is being sold in some licensed venues around Adelaide The SA Opposition says the behaviour is clearly to "encourage problem gamblers"

The SA Opposition says the behaviour is clearly to "encourage problem gamblers" But a jeweller says customers only get paid in cheques, not cash

But an Adelaide-based jeweller denies he has done "anything wrong", saying he pays his customers in cheques for safety reasons, meaning the money received cannot be used for the pokies.

The Opposition accused Hallmark Jewellers of offering to buy gold from vulnerable people.

Member for Wright Blair Boyer said the issue first came to his attention last month, when a resident in his electorate told him the gold-buyer had advertised an event at the Village Tavern at Golden Grove, which he said had 40 poker machines.

Labor MP Blair Boyer and Opposition Leader Peter Malinauskas talk about the issue. ( ABC News: Isabel Dayman )

"I was first given a copy of [a] flyer by a concerned resident of the north-east suburbs, and I honestly thought that was a hoax," Mr Boyer said.

"I don't think that any fair-minded South Australian would find it easy to accept that this sort of predatory behaviour is permissible in our society.

"These kind of behaviours … are clearly designed to encourage problem gamblers, who are most likely to put every last dollar into a pokies machine, to come next door and trade in the wedding ring or the family heirloom, so they can go back to the pokies and keep on gambling."

However, Hallmark Jewellers owner Arthur Perelman said he had operated mobile gold-buying services across the state for several years, and only a handful of the venues he had used included poker machines.

Some of the jewellery on sale at Hallmark Jewellers. ( ABC News: Isabel Dayman )

"I've done nothing wrong," Mr Perelman said.

"I have a duty of care to my staff not to carry cash on them so that I don't have some clown coming in [demanding] cash — that's why we don't use cash."

An event has been cancelled at the Alberton Hotel in Adelaide. ( ABC News: Isabel Dayman )

Mr Perelman said he would rethink the kinds of venues he used for the mobile side of his business, now that the issue had been "brought to [his] attention".

"This has become a circus," he said.

"[Gambling venues] represent such a small number, that I would say they are 4 per cent, or 6 per cent of my venues.

"[The rest] are service clubs, town halls, non-profit-making [venues], who rely on people like me to hire their halls.

"We only use pubs where we can't get into a hall. And remember, we get a separate room in a pub — separate from the knowing of the gambler."

Gold-buying event cancelled after backlash

A gold-buying event had been planned for the Alberton Hotel on Monday, but the event was cancelled at the last minute after Mr Perelman received a call from the Australian Hotels Association.

Mr Boyer said he would introduce a bill to Parliament in the next sitting week, to create penalties for licensed gaming venues that allowed second-hand dealers to operate on their site, and for trading businesses who sought to use a licensed venue for buying and selling.

But Attorney-General Vickie Chapman said new legislation was unnecessary, as any change could be achieved through the industry's Code of Conduct.

Ms Chapman speaks to reporters about a pawnbroker setting up in a pub in Adelaide. ( ABC News: Isabel Dayman )

"As it happens, the situation has been this for 35 years — the practice of second-hand operations in hotels," Ms Chapman said.

"This has been brought to the attention of the Commissioner for Business Services … arising out of the complaint by the Labor Party that a pamphlet had been distributed [around Golden Grove].

"[The Commissioner] has determined that this action is not in breach of any code of practice in relation to licensed venues.

"However, he's confirmed with me that this will be under consideration in the redrafting of the new codes of practice.

"The reality is that in this case, existing law covers for the structure, and the structure incorporates a code of practice, and that is under review."