After being gently told they are working too hard and instructed to find a hobby, many a man may have grudgingly taken up gardening, an evening class or signed up to the local gym.

For one businessman, however, that moment was the start of something rather different: a multi-million-pound new sideline which led to becoming a world-authority on stamps.

Alan Holyoake, who made his fortune in the fish business, has become one of the world's most successful stamp collectors, currently honoured at the Smithsonian Museum for the extraordinary discovery of the world's first official stamp.