A man who claims he killed his father while sleepwalking has undergone extensive tests, a court has heard.
Jules Lowe's sleeping patterns were tested by scientists
Jules Lowe, 32, of Walkden, Greater Manchester, denies murdering Edward Lowe, 83, on the grounds of automatism.
Manchester Crown Court heard scientists made him drink alcohol in an effort to replicate the drunken state he was in on the night his father died.
Dr Peter Fenwick said Mr Lowe could have been asleep when he killed his father but could not say for certain.
Mr Lowe is accused of punching, kicking and stamping on his father.
Dr Fenwick told the jury his sleep patterns were tested on five separate occasions, after drinking, when sober and when he had been deprived of sleep for 36 hours.
He said during the examinations, Mr Lowe did become "irritable" and "socially inappropriate".
"The tests were the most detailed scientific tests in British legal history," he added.
He said Mr Lowe had not started sleepwalking during any of the tests, but decided he was a sleepwalker because of his history of such behaviour based on evidence from his friends and family.
But when questioned by Richard Marks QC, prosecuting, he admitted there was "not a shred" of evidence to show the killing happened while Mr Lowe was sleepwalking.
He admitted Mr Lowe had not been violent during previous sleepwalking episodes, but could not rule out the possibility that he had killed his father while asleep.
The case continues.