A former employee of the British Secret Intelligence Service (SIS) has been sentenced to 12 months in prison for attempting to sell top secret information to a foreign government.

Daniel Houghton, who worked for the SIS between September 2007 and May 2009, had access to computer files belonging to the British Security Service, MI5. He copied some of the files, which were classified as secret to top secret, and tried to sell the information to the Dutch intelligence service.

The files related to the work of the security and intelligence services, including intelligence gathering tools developed by SIS staff for national security purposes.

The 25-year-old phoned the Dutch intelligence service, offering to sell the information to them in August 2009, after leaving SIS. He maintained contact with the Dutch intelligence service and even flew out to Holland in January 2010.

However, the Dutch had alerted the British intelligence service to Houghton’s plans. MI5 and MPS Counter Terrorism Command caught Houghton in a covert operation, whereby he accepted a suitcase containing £900,000 in cash [as pictured] for the information, at a central London hotel.

As well the computer files, Houghton had also offered lists containing details of his former SIS colleagues who were involved in security and intelligence work. He had initially asked for £2 million, but settled on the lower fee.

Houghton was sentenced to 12 months for each of two counts, to run concurrently, of breaching the Official Secrets Act. He pleaded guilty to the offences at a hearing at the Royal Courts of Justice on 14 July 2010.

Deputy assistant commissioner Stuart Osborne, senior national co-ordinator of counter terrorism, said: "Daniel Houghton gravely betrayed his former work colleagues by trying to sell this secret information, which, had it fallen into the wrong hands, could have compromised the work of the British Security Services.