News Corporation head Rupert Murdoch has defended a move to start charging for access to the company's online content.

The new policy was announced in August and has been attacked by ABC managing director Mark Scott, who called it the classic play of an empire in decline.

But the media mogul has told Sky News that online media content should never have been completely free.

"It costs us a lot of money to put together good newspapers and good content," he said.

"And they're very happy to pay for it when they buy a newspaper, and I think when they read it elsewhere they're going to have to pay.

"[It won't cost] huge sums - you'll be surprised at how much can be done, how cheaply, into the average home."