A post-mortem examination into the death of a 64-year-old man who was "tormented" by yobs has proved inconclusive, police.
Detectives ordered further tests to be carried out on the body of David Askew, who was found dead outside his home in Hattersley, Greater Manchester, on Wednesday night.
An 18-year-old man was arrested on suspicion of manslaughter on Thursday.
Officers were called to his Melandra Crescent address after reports that youngsters were causing an "annoyance" at the property.
They found Mr Askew, who had learning difficulties, collapsed outside and he was pronounced dead at the scene.
A Greater Manchester Police spokeswoman said: "A post-mortem examination into the death of David Askew has proved inconclusive. Further tests will have to be carried out to determine the exact cause of the 64-year-old's death. An 18-year-old who was arrested on suspicion of manslaughter remains in police custody for questioning."
It emerged that the authorities were warned years ago that he was being targeted by gangs where he lived with his wheelchair-bound mother Rose and his brother Brian.
One neighbour said Mr Askew had been "tormented to death - like bear-baiting".
Mr Askew's mother paid tribute to her son, saying "he wouldn't hurt a fly".
In a statement issued by Greater Manchester Police (GMP), she said: "Throughout the day I have seen and heard different reports by the press about my son and about what has happened. I just want to say that David was a very happy person. He was kind and thoughtful. He was a true gentleman and would often help me around the house and with shopping. He wouldn't hurt a fly and he never saw bad in anyone. He always put others first."
