Detectives have been given another 36 hours to question a man from County Durham on suspicion of murdering his parents.
Police found the bodies of Bob Seddon, and his wife Patricia, at their home in Sale in Greater Manchester, on Friday.
Nic Seddon, 45, was arrested at his home in Seaham the following day. A post-mortem examination confirmed the couple died of gunshot wounds.
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They took a vehicle from Newcastle before driving to North Shields, where they collided with a 72-year-old and left him for dead.
Roger Burrell from Chester-le-Street broke the European record in the 84-89 years category in the 100m in May.
GSK said the cash boost would help build a new sterile facility at Barnard Castle and will create jobs