New South Wales has become the latest gaming jurisdiction to signal a clampdown on online bookmakers including Lottoland who take bets on lottery outcomes, a business sometimes referred to as "synthetic lotteries".

"Synthetic lotteries do not have the same level of consumer protection as domestic lotteries," Deputy Premier John Barilaro said.

"Our concern is that many customers buy tickets in a synthetic lottery, believing they're entering a lottery, when in fact they are betting on the outcome of that lottery."

Unlike synthetic lotteries, Mr Barilaro said, domestic lotteries had guaranteed prize pools and were bound by strict terms and conditions and robust regulations.

The NSW government was now "considering options to restrict betting on these lotteries", a statement said.

It comes after the state government in Victoria recently revealed it planned to overhaul gambling laws to allow it to restrict "exotic" forms of wagering, such as betting on the outcomes of overseas-based lotteries.

Gibraltar-based Lottoland has been the target of coordinated attacks by Australian lotteries giant Tatts and industry groups representing thousands of the country's newsagencies. They claim Lottoland's "fake" lottery service is cutting into their livelihoods and eroding tens of millions of dollars in tax revenue that would otherwise pay for schools, hospitals and roads.

The campaign, dubbed "Lottoland's Gotta Go", includes newspaper and television advertisements, and posters in newsagencies Australia-wide.

Lottoland chief executive Luke Brill on Thursday hit back at the mounting criticism, saying the company had become the target of a "smear campaign" orchestrated by Tatts in order to "protect its monopoly".

"The reality is we are just under 1 per cent of the market," Mr Brill said.

"The deficit they are talking about in their numbers simply doesn't add up."

He denied claims that Lottoland was cutting into newsagents' customers and revenue base.

"The majority of our customers have never stepped foot in a newsagent's," he said.

"They are predominantly sports betters ... we have tapped into a different type of consumer."

The Australian Lottery and Newsagents Association welcomed the NSW government's latest announcement.

"Online bookmaking sites that offer bets on lottery outcomes threaten the significant state tax revenue generated by lotteries, hurts small business, and, in many cases, are misleading to consumers," association chief executive Adam Joy said.

"This also sends a clear message to any business that is deliberately or unintentionally misleading NSW consumers, that it won't be tolerated or overlooked. And we call on other state governments to do the same."

Lottoland, like many other online wagering companies, are registered in the Northern Territory, where tax rates for the bookmakers are much lower than in other states.

But online wagering companies have recently been hit with a 15 per cent "point-of-consumption tax" introduced in South Australia, and there are plans being considered for a national scheme.

Lottoland's Mr Brill on Thursday said point-of-consumption taxes were a good way to ensure "revenue flows back to the states".