News Corp boss Rupert Murdoch has strongly hinted that he will start taking legal action against various media outlets, after a series of damning allegations against his companies.

A BBC Panorama programme broadcast on 28 March alleged that former News Corp subsidiary NDS, a pay-TV smartcard manufacturer, used online piracy to take down Murdoch's TV rivals by leaking encryption codes on the web.

Similar allegations against NDS recently appeared in Australia.

Murdoch's UK newspaper business, News International, has also been mired in scandal with the ongoing phone hacking and corruption police probes engulfing it, leading to near-daily allegations and revelations.

"Seems every competitor and enemy piling on with lies and libels. So bad, easy to hit back hard, which preparing," Murdoch tweeted.

"Enemies many different agendas, but worst old toffs and right-wingers who still want last century's status quo with their monopolies.

"Let's have it on! Choice, freedom of thought and markets, individual personal responsibility."

News Corp's President Chase Carey has also lashed out.

He called the BBC's allegations "unfair and baseless" and reiterated a letter to Panorama from NDS executive chairman, Abe Peled, calling for a retraction.