Rupert Murdoch has launched a spirited defence of putting up paywalls around his newspaper websites, while embracing the game-changing potential of Apple's iPad. The News Corporation chairman hailed the device as a possible saviour of the newspaper industry.

Murdoch renewed his attacks on search engines, such as Google, which he accused of stealing journalism from regular media outlets. He told a US National Press Club event at George Washington University the newspaper industry had to stand up for itself and charge for content, while using copyright law to defend its journalism from being used without its permission.

Rupert Murdoch hopes digital subscriptions via the iPad will offset decline in newspaper sales

''We are going to stop people like Google or Microsoft or whoever from taking stories for nothing … there is a law of copyright and they recognise it,'' he told a packed audience of students, journalists and other media professionals.

He said search engines had tapped into a ''river of gold'' by aggregating content but that the days of free news had to come to an end. ''They take [news content] for nothing. They have got this very clever business model,'' Murdoch said.