An investigation by the Australian Communications and Media Authority before and during the 2023 sporting event found 18 offshore websites had breached gambling laws.

Gambling such as online casinos and pokie machines as well as betting on sporting events while play is under way is illegal.

The watchdog probe investigated 200 offshore gambling websites ahead of the world cup, which Australia co-hosted with New Zealand.

Of those, 21 were investigated by the authority due to them directly targeting Australian punters, with 18 breaching laws.

Three of the offshore gambling websites withdrew from Australia following the investigation, while the remaining 15 were blocked by internet providers following requests by the watchdog.

The authority's online gambling lead Carolyn Lidgerwood said many of the websites targeted Australian gamblers.

"Illegal gambling operations often take advantage of high-profile sporting events to push their services onto fans," she said.

"These sites also offer none of the consumer protections that apply to licensed wagering services in Australia.

"Using these sites is more than a gamble as you have no rights, and even if you win, you may never see the money."

The crackdown comes as a parliamentary committee recommended gambling advertising be phased out within three years.

Federal parliament had passed legislation in December banning the use of credit cards or digital currency to gamble online.

Since 2019, more than 900 gambling website have been blocked since the media watchdog have been tasked with asking internet providers to crack down on illegal websites.

It's estimated more than 220 websites have pulled out of the Australian market since the rules were enforced.

Australian Associated Press