A keen sportsman and biologist died after apparently running into a low-hanging high-voltage cable. James Kew, 41, from Ashdon, Essex, was leading a run with three others when he collided with the cable in a field in nearby Newport at about 8.40pm on Tuesday.
Police, firefighters and paramedics were called but he died instantly. Two others suffered minor injuries. It is thought the cable, which carried about 11,000 volts, was hanging across the path.
Dr Kew was a leading member of the Saffron Striders running club and played for Bishop's Stortford Hockey Club.
A statement on the Saffron Striders' website said: "It is with the deepest regret we have to announce the death of James Kew, as a result of a tragic accident whilst out running."
Dr Kew had worked as a director of biology in the research department at GlaxoSmithKline since 2010. His family was said to be distraught and have asked not to be approached.