Google has hit back against criticisms by Rupert Murdoch's News Corp, arguing the US internet giant has done more than "almost any other company to help tackle online piracy" and denying its online search power is anti-competitive.

Google published a blog titled 'Dear Rupert' on Thursday, laying out a detailed response to a public attack by News Corp, publisher of The Australian, Wall Street Journal and other titles.

News Corp has accused Google of being willing to “exploit its dominant market position to stifle competition” and being a “platform for piracy and the spread of malicious networks”. Credit:Getty Images

The chief executive of US-headquartered News Corp, Australian Robert Thomson, sent an open letter last week to the European Commission complaining about Google and demanding its "overwhelming" influence be reined in.

Mr Murdoch's key lieutenant accused the internet giant of being willing to "exploit its dominant market position to stifle competition" and being a "platform for piracy and the spread of malicious networks".