A British man is "likely to have been killed" at the hands of his captors in Nigeria in an "act of cold-blooded murder", Foreign Secretary William Hague has said.
The construction worker, who had been held hostage since February 16, is believed to have been killed alongside six other foreign nationals.
In a statement, Mr Hague said: "It is with deep sadness that I must confirm that a British construction worker, held hostage in Nigeria since 16 February, is likely to have been killed at the hands of his captors, along with six other foreign nationals who we believe were also tragically murdered.
"This was an act of cold-blooded murder, which I condemn in the strongest terms.
"My thoughts are with his family, and the families of the other hostages, who will be devastated by this tragic loss.
"I offer them our deep condolences at this terrible time, and know that the thoughts of people up and down our country will be with them.
"I ask the media to allow them time to come to terms with their loss in privacy.
"Responsibility for this tragic outcome rests squarely with the terrorists. I am grateful to the Nigerian Government for their unstinting help and co-operation.
"We are utterly determined to work with them to hold the perpetrators of this heinous act to account, and to combat the terrorism which so blights the lives of people in Northern Nigeria and in the wider region."