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.

The crewman worked on what has become known as the 'Ambulanza della morte', or the Ambulance of Death

They think Mr Garofalo, a father of three, sent the dead patients to funeral businesses with links to organised crime, for which he was paid 300 euros a corpse.

His alleged three victims were a 55-year-old man, an elderly man and an elderly woman.

They were all reportedly terminal ill and the ambulance was taking them from the hospital to their homes so they could die in peace with their loved ones.

Another three alleged accomplices are being investigated by police.

Sicily remains one of Italy’s poorest regions, in part a result of the stranglehold of the mafia.

The gruesome practice emerged earlier this year from a television investigation, in which an alleged accomplice-turned-informant, a 28-year-old local, said: “People were not dying by the hand of God.”

Raffaele Covetti, a senior police officer, said: “This was a particularly cruel way for these people to die.”

Andrea Bonomo, an anti-mafia investigator, said: “They all had the trust they put in him as a stretcher-bearer betrayed.”

Before finding a job as ambulance crew, the suspect had worked on the slopes of Mt Etna, the hulking volcano overlooking Catania, picking oranges.