A man who shook his newborn son, causing catastrophic brain injuries that were said to have led to the child’s death more than a decade later, has been found not guilty of manslaughter following a landmark trial.

Allan Young, 36, broke down in tears at the Old Bailey as the jury returned a verdict of not guilty.

Mr Young had previously been jailed for 12 months after admitting causing grievous bodily harm to five-week-old Michael Winn at their home in Belsize Road, Kilburn, in 1998, leaving him “severely disabled”, the court heard.

When Michael died in 2011, Mr Young was further charged with manslaughter following a change in the law.

Before 1996, charges of murder or manslaughter could only be brought if death occurred within a year and a day from the date of the original assault.

In Mr Young’s case, charges were brought even though there had been a 12-year gap, making it the longest on record.

The prosecution said Michael’s death was a direct result of the injuries he suffered years earlier which caused cerebral palsy and curvature of the spine.

His physical and intellectual development was impaired to such an extent he had trouble breathing, was blind, incontinent and could not speak.

Following the assault, Michael was assessed as having only a 65% chance of surviving to the age of 11, the court heard.

Mr Young, of Stevenston in Ayrshire, Scotland, had denied manslaughter.

Today, after 24 hours and 40 minutes’ deliberations, a jury of ten people reached a verdict which found him not guilty.

Mr Young declined the judge’s offer to remain in the court after being freed from the dock, and also declined to comment as he left the court room.