A Friends Reunited user was hacked to death by a knife-wielding Sardinian love rival, a court was told yesterday. Francesco Matta allegedly knifed RAF officer Stephen Keen four times through the neck, causing fatal injuries.

Boasting to police shortly after his arrest, Matta said: "I am an executioner. I hit the man. I came here to kill the man."

Matta's wife, Susan, rediscovered childhood sweetheart Stephen Keen through social networking site Friends Reunited and soon started a secret relationship. But the prosecution allege that this sent Matta over the edge, and say he hunted Keen down and murdered him to make his wife "suffer as I am suffering".

Keen and Mrs Matta had only just settled down in Tiverton, Devon, when Keen was brutally murdered. The jury in the case has been told that Matta wil admit the slaying, but should be found guilty of manslaughter by reason of diminished responsibility.

The trial goes on.