The communications watchdog wants to block a string of illegal gambling websites.

The Australian Communications and Media Authority (ACMA) is looking at using new powers to take enforcement action against the sites.

Authorities say Australians spend hundreds of millions of dollars on the dodgy sites each year, but often face difficulties recouping their winnings or deposits.

“Too often these offshore operators are defrauding Australians and their websites typically provide very few, if any, harm minimisation controls,” Federal Communications Minister Paul Fletcher said.

The ACMA gained new powers as a result of a 2015 review of interactive gambling.

The review, overseen by former NSW premier Barry O'Farrell, made 19 recommendations to the government.

It raised gambling sites specifically, saying they lack Australian consumer protections and have links with organised crime.