LONDON, England (CNN) -- British Prime Minister Gordon Brown says there's "strong reason to believe" a British citizen has been killed by an al Qaeda cell in the west African nation of Mali.
"We have strong reason to believe that a British citizen, Edwin Dyer, has been murdered by an al Qaeda cell in Mali," Brown said in a statement Wednesday. "I utterly condemn this appalling and barbaric act of terrorism."
The British government did not say why it believes he is dead.
Dyer was kidnapped in neighboring Niger in January, but was being held in Mali by the cell. He was taken along with a Swiss tourist, who is still being held captive, while attending a festival near the border with Mali.
The group had said it would kill Dyer if the British government refused to release radical Muslim cleric Abu Qatada, who is awaiting extradition to Jordan, from a UK prison.
While in Britain, Qatada was convicted of terrorism offences by a Jordanian court and faces life in jail.
"This tragedy reinforces our commitment to confront terrorism. It strengthens our determination never to concede to the demands of terrorists, nor to pay ransoms," Brown said.
"I want those who would use terror against British citizens to know beyond doubt that we and our allies will pursue them relentlessly, and that they will meet the justice they deserve."