GCHQ 'set up fake LinkedIn profiles to spy on mobile phone networks' according to documents leaked by Edward Snowden British spies apparently spied on security staff at European telecoms firms Set up copies of LinkedIn pages which infected computers with malware Targeting telecommunications allows spies access to individuals' profiles GCHQ set up fake pages on LinkedIn and other websites in order to spy on communications firms, it has been claimed. Leaked documents apparently reveal that the British surveillance service targeted security staff responsible for safeguarding networks across Europe. The claim is likely to lead to further controversy among Britain's allies coming just a week after it was reported that the UK was spying on Germany via its embassy in Berlin. Claims: Spies at GCHQ, whose headquarters are pictured, are alleged to have hacked into telecoms firms German magazine Der Spiegel reported that one tactic used by GCHQ to monitor mobile phone and internet traffic was to install 'malware' via dummy copies of popular websites. British spies apparently found out which employees of Belgium's state-owned telecoms firm Belgacom used business network LinkedIn and other sites, including tech news forum Slashdot. They then created copies of LinkedIn pages which were indistinguishable from the originals but which secretly installed software on the users' computers, the magazine reported. This malware, installed by a process known as 'Quantum Insert', allegedly gave GCHQ access to the company's routers. Communications networks are particularly valuable to spies, because they allow instant access to individual users. Defence: The agency's director Iain Lobban insists its work is essential to national security Other companies prioritised by GCHQ, according to Der Spiegel, were companies which process billing payments between mobile phone companies in different countries. Spies are alleged to have hacked in to the computers of engineers at Comfone and Mach, both largely unknown to the general public but key to international communications networks. By infiltrating telecoms companies, Britain is apparently able to compile detailed portraits of suspects' lives. Leaks: The latest allegations came from documents obtained by contractor Edward Snowden In one case, Der Spiegel reported, the firm drew up a list of multiple computers used by an employee of Mach, as well as his Skype, Gmail and social networking accounts. The latest hacking allegations were brought to light in secret documents leaked by former U.S. government contractor Edward Snowden. They are believed to centre around a GCHQ department called 'My Network Operations Centre', or MyNOC, which brings together key staff from different divisions to work on infiltrating international telecommunications. One leaked document shows Prince Charles and the Duchess of Cornwall visiting MyNOC for a briefing on Afghanistan. A LinkedIn spokesman told Der Spiegel: 'We were never told about this alleged activity and we would never approve of it, irrespective of what purpose it was used for.' The spying claims have prompted a furious reaction within Belgium, where public prosecutors have launched an investigation. Last week, the British ambassador to Germany was summoned to meet government officials over allegations that GCHQ had installed a 'listening post' on top of the British embassy. And over the weekend an Icelandic politician claimed that the UK spied on officials who were negotiating over the collapse of the country's banks. GCHQ's head, Iain Lobban, delivered a robust defence of the agency's work when he appeared in front of MPs at a select committee hearing last week. The agency has refused to comment on the latest allegations. Edward Snowden, a former contractor at America's National Security Agency, has rocked the intelligence world by leaking secret documents which reveal the previously unknown extent of global spying. While most of his revelations involved the NSA, he has also made a number of disclosures about GCHQ, which shares intelligence with the U.S. and other close allies. It emerged that British spies regularly tap in to the fibre-optic cables which carry internet traffic around the world, co-operating with telecoms firms to intercept data. The programme, known as 'Tempora', is meant to target terror suspects but also collects information about millions of innocent people. Documents passed to newspapers by Mr Snowden showed GCHQ also monitors emails sent using popular services such as Gmail, Yahoo and Hotmail. A diplomatic outcry ensued when it emerged that Britain had spied on the leaders of other governments during the G20 summit in London in 2009. And last week the German government - already furious that the U.S. had been tapping the phone of chancellor Angela Merkel - summoned the British ambassador for a meeting over claims that the UK embassy was used for spying by GCHQ.