There is a greater threat to privacy from private companies than intelligence agencies as they snoop more customer data and share them with each other and authorities, said GCHQ director Sir Iain Lobban in an interview with The Telegraph.

Commenting on an ongoing row over the level of snooping powers to be given to the police and intelligence agencies, Sir Iain told the paper: "Look, who has the info on you? It’s the commercial companies, not us, who know everything – a massive sharing of data."

He warned the public to be more concerned about what private companies are doing with their personal information.

His statement came as reports surfaced about three of the UK’s main mobile phone companies, including EE, Vodafone and Three sharing data on customers to the police automatically, if asked.

While EE responded that the system was automated but subject to oversight, Vodafone has accepted that though the requests are being processed automatically, it was done within Regulation of Investigatory Powers Act (Ripa) framework. Three said that it was following the legal requirements.

As per Ripa, which was designed to counter terrorism, the authorities are allowed to access phone and Internet records.

The Telegraph’s investigation has revealed that phone companies rarely review the data and instead, process it on an automated system, before it is passed on to the police.

Commenting on this, Eric King, deputy director of Privacy International, said: "If companies are providing communications data to law enforcement on automatic pilot, it’s as good as giving police direct access."

Despite the criticism, UK Home Secretary Theresa May wants snooping powers to expand, in order to improve the surveillance activities, because terrorists are using social media and chat rooms that are not tracked properly by Internet companies.

In an attempt to expand the snooping powers May is planning to revive the proposal named ‘the snooper’s charter’ that was written off by The Liberal Democrats previously.