AN inquest has been unable to solve the mystery of a security guard's sudden death.

Peter Douglas, 37, collapsed at his east Cleveland home in front of his mother, the coroner heard yesterday.

Despite extensive forensic tests and a post-mortem examination, medical experts were unable to discover why he died, in June last year.

Consultant pathologist Campbell Ritchie told the Middlesbrough inquest that it was an extremely rare case, with no sign of injury or any significant abnormalities.

GP Gillian Coleclough said Mr Douglas, of Hambleton Crescent, Marske, complained of vomiting and abdominal pain, but the post-mortem examination found nothing.

Coroner Michael Sheffield recorded a verdict of natural causes, saying: "The evidence makes it clear that his death was sudden and unexpected, but precise cause of death cannot be ascertained."