British spooks intercepted emails from US and UK media organisations and rated ‘investigative journalists’ alongside terrorists and hackers as potential security threats, secret documents reveal.

Internal advice circulated by intelligence chiefs at the Government spy centre GCHQ claims ‘journalists and reporters representing all types of news media represent a potential threat to security’.

Intelligence documents leaked by the fugitive US whistleblower Edward Snowden also show that British security officers scooped up 70,000 emails in just 10 minutes during one interception exercise in 2008.

Among the private exchanges were emails between journalists at the BBC, New York Times and US network NBC.

The Government Communications Headquarters (GCHQ) is Britain's eavesdropping centre in Cheltenham, Gloucestershire

The disclosure comes amid growing calls for the security services to be handed more power to monitor the internet following the Paris terror attacks.

Internal security advice, shared among British intelligence agencies, scored journalists in a table of potential threats.

One restricted document, which according to the Guardian was intended for those in army intelligence, warned that ‘journalists and reporters representing all types of news media represent a potential threat to security’.

It continued: ‘Of specific concern are “investigative journalists” who specialise in defence-related exposés either for profit or what they deem to be of the public interest.'

The document adds: ‘All classes of journalists and reporters may try either a formal approach or an informal approach, possibly with off-duty personnel, in their attempts to gain official information to which they are not entitled.’

It warns staff that ‘such approaches pose a real threat’, adding it must be ‘immediately reported’.

One table scored journalists a ‘low’ information security risk – compared to terrorists who are seen as a ‘moderate’ threat.

David Cameron has promised to give the security agencies more powers to monitor people's emails and internet use

The latest revelations about GCHQ are buried in documents leaked by the fugitive whistleblower Edward Snowden

A spokesman for GCHQ refused to confirm or deny if the leaked documents were accurate. The spokesman said: ‘It is longstanding policy that we do not comment on intelligence matters.

‘Furthermore, all of GCHQ’s work is carried out in accordance with a strict legal and policy framework, which ensures that our activities are authorised, necessary and proportionate, and that there is rigorous oversight, including from the secretary of state, the interception and intelligence services commissioners and the parliamentary intelligence and security committee.

‘All our operational processes rigorously support this position. In addition, the UK’s interception regime is entirely compatible with the European convention on human rights.’

According to the Guardian, GCHQ scooped up emails to and from journalists during one 10-minute 'tapping' session in November 2008.

Emails from the BBC, the Sun and the Mail on Sunday were picked up and shared on the agency’s internal computer system - alongside memos from US media organisations.

The revelation comes as the British government faces growing pressure to ensure journalists’ texts and emails are protected from snooping.