An Italian ambulance stretcher-bearer has been arrested on suspicion of injecting air into patients’ veins and “selling” their bodies to a funeral parlour for 300 euros a go, in an operation with alleged links to the Sicilian mafia.

Davide Garofalo, 42, from Sicily, is alleged to have killed at least three people with the injection method, and possibly up to 50.

In what has been dubbed the “ambulance of death” investigation, Mr Garofalo is accused of secretly injecting air as patients were transported, killing them by triggering an embolism - the obstruction of an artery, usually with an air bubble or clot of blood.

Police are now analysing around 50 suspicious deaths that took place in the town of Biancavilla near Catania in eastern Sicily in a four-year period ending last year.

They are working on the theory that the stretcher bearer may have been working in cooperation with a local clan from Cosa Nostra, the Sicilian mafia.