A British man has been killed in Sokoto, Nigeria, during an attempted rescue operation after being taken hostage in the country last May.
Chris McManus was taken captive by terrorists with his Italian colleague Franco Lamolinara. Both men are believed to have been killed by their captors.
His family issued a statement in which they said they were "devastated" by the news:
"As a family, we are of course devastated by the news of Chris’ death which we received earlier today.
"During this ordeal we have relied heavily on the support of our family and friends which has never waned and has enabled us to get through the most difficult of times."
Thanking those involved in the rescue attempt, the family said: "We knew Chris was in an extremely dangerous situation. However we knew that everything that could be done was being done."
The family added: "We now need time to grieve and come to terms with our loss. We would therefore be grateful if you would respect our privacy at this most difficult of times."
Nigerian President Jonathan Goodluck has condemned the killing of the hostages. He said in a statement that "the perpetrators of the murderous act, who have all been arrested, would be made to face the full wrath of the law," AP reported.
David Cameron said in a statement that he had authorised a rescue mission to go ahead today, saying there was "reason to believe that their lives were under imminent and growing danger."
"Preparations were made to mount an operation to attempt to rescue Chris and Franco. Together with the Nigerian Government, today I authorised it to go ahead, with UK support.
"It is with great regret that I have to say that both Chris and Franco have lost their lives," he said, adding: "I am very sorry that this ended so tragically".
"Our immediate thoughts must be with Chris and Franco's families, and we offer them our sincerest condolences," Cameron said.
"Both families have endured a terrible ordeal, and this is a devastating moment for all of them."
In December last year, a Nigerian group calling itself "Al Qaida in the land beyond the Sahil" announced it had captured McManus.
It released a hostage video to Nouakchott News Agency claiming it had kidnapped the Briton and showed a blindfolded and bearded man in an orange vest.
Three men in dark clothing stood behind him armed with rifles and a machete.
It was reported that the man pictured in the video called for the British government to respond to the demands of the group, so they would spare his life.
He also asked for the British people to pressure the government to answer the demands of the group so he could return to his family.
McManus, a contract worker for the construction company B.Stabilini, was kidnapped by a "horde of gunmen" in May last year.
Raiders stormed his apartment in Birnin-Kebbi, in the north west of the country, and captured him along with Lamolinara.
A German colleague managed to escape by scaling a wall but a Nigerian engineer was shot and wounded in the raid.
The men were in the city building a bank.
The were held in Sokoto, a city in Nigeria's north west, the Foreign Office confirmed.
There were reports of a house being surrounded by military and the sounds of gunfire heard before an ambulance was called.
Security forces had also set up a cordon around the site.
The Italian government said the rescue mission was a joint endevour between British and Nigerian forces, according to Reuters.
Labour leader Ed Miliband condemned the "callous cruelty" of the kidnappers: "Our hearts go out to the families of Chris McManus and Franco Lamolinara.
"Their murder is a horrific event. I condemn unreservedly the callous cruelty of their kidnappers and we pay tribute to those who risked their lives in attempting to rescue them," he said in a statement on Thursday.
There have been a number of foreigners kidnapped while working in Nigeria in recent years.
In September 2008 two Britons were held by the Movement for the Emancipation of Niger Delta.
A Scottish oil worker was abducted and his guard killed in April 2009, in the Rivers State capital Port Harcourt.
Three Britons and a Colombian were kidnapped in January 2010 and in November of the same year, four men from the US, Canada and France were taken 7.5 miles offshore on the Okoro field.
In January last year two French hostages were kidnapped from Niamey, the capital of neighbouring Niger to Nigeria's north.