A body handed to the British authorities in Iraq is that of Alec MacLachlan, Gordon Brown confirmed last night.
The Prime Minister announced with “deepest regret” that Mr MacLachlan's remains had been identified.
He vowed to bring the terrorists responsible for the murder to justice and said the thoughts of the whole country were with Mr MacLachlan's family.
Mr MacLachlan was captured in 2007 along with fellow security guards Jason Swindlehurst and Jason Creswell, whose bodies were found earlier this year, and the man they were guarding, IT consultant Peter Moore. Another guard, Alan McMenemy, is still missing.
Mr Brown said: “It's with the deepest regret that the body passed to the British Embassy is now discovered to be that of Alec MacLachlan. My thoughts, and I believe the thoughts of the whole country, are with the family at this time of great grief.
“No family should have to endure what they have gone through, the loss through the hostage-taking, then the period of silence and not knowing what is happening, and now to find that their loved one is lost.”
Six weeks ago, the Foreign Office told the families of Mr MacLachlan, from Llanelli, south Wales, and Mr McMenemy, from Glasgow, their loved ones were “very likely” to have died.
The five Britons were seized by about 40 armed men wearing police uniforms at the finance ministry in Baghdad on May 29, 2007.
The bodies of Mr Swindlehurst, from Skelmersdale, Lancashire, and Mr Creswell, originally from Glasgow, were handed over to Baghdad officials in June.
The kidnappers, calling themselves the Islamic Shiite Resistance in Iraq, have issued several videos featuring the captives and making demands.
In February last year, a video broadcast by a Dubai-based TV station showed a bearded and tired-looking Mr Moore asking Mr Brown to free nine Iraqis in exchange for the British hostages.