Turnbull says ASIO 'not interested in Game of Thrones'

Communications Minister Malcolm Turnbull has dismissed suggestions police and spy agencies may use metadata to catch people illegally downloading TV shows and movies.

He says authorities have better things to do.

"The Australian Federal Police and ASIO frankly are not interested in whether you are illegally downloading a copy of the Game of Thrones," he told ABC television on Friday.

"That's a bad thing to do, but I can tell you our national security agencies have got other things on their mind."

The government's third tranche of anti-terrorism legislation would require companies to hold on to metadata - background information about calls and internet usage but not the content itself - for at least two years.

The plans have prompted concern agencies may be able to use the data to catch Australians illegally downloading media content.

Telcos already collect metadata for the purposes of billing, however many delete the information due to the cost of retaining it.

Mr Turnbull said the policy was purely about "standardising an existing practice" and the government was not going after people breaching copyright.