Alex Torbet is Britain's equivalent of the Birdman of Alcatraz.

After a distinguished RAF career he murdered his wife and father-in-law in an uncontrollable fit of anger, and in 1979 was sentenced to life imprisonment.

In Saughton Prison, Edinburgh, Torbet became interested in the fish in the prison's aquaculture unit, attached to Stirling University, and was soon saving the university a huge amount of money thanks to his skill in breeding both fish and shellfish for their experiments.

He was particularly drawn to a species called tilapia, whose ability to provide high-protein food from a diet of rubbish gave it great potential as a source of food for poor countries. He developed a golden strain, attractive as well as nutritious, which is now helping to feed the Third World.

Due for release this year, Torbet was hoping to continue his work at Stirling, but the university had reservations about his joining their team. QED examines his life and work behind bars, and his hopes for the future.

(Birdman of Alcatraz is shown at 11.30 pm)

A Sparta production for BBCtv