Alder Hey has the biggest collection - over 2,000 - of paediatric hearts in the country, amassed over 50 years.

'This is a vital resource in the hospital's attempts to improve the outcomes for children undergoing paediatric heart surgery. Alder Hey's death rates for open heart surgery have reduced from 17 per cent 10 years ago to 3 per cent last year, ' says a spokesperson.

The other collection of organs is more contentious. Professor Dick Van Velzen, a histopathologist - a specialty that examines tissue samples - and Britain's first professor of infant and foetal pathology, was employed by Liverpool University and based at Alder Hey. Professor Van Velzen retained 850 sets of children's organs, including hearts, lungs, brains and abdominal organs. He is currently living in the Netherlands.