Police in Sicily have arrested a stretcher-bearer suspected of injecting air into the veins of patients to kill them, then collecting €300 (£265) in cash from local funeral parlours in a grisly scam allegedly run by the mafia.

Working on what the Italian media has dubbed the “ambulanza della morte”, or ambulance of death, Davide Garofalo, 42, faces charges of voluntary homicide over the deaths of at least three people and possibly dozens more.

He is accused by police in Catania of secretly injecting air into the veins of an elderly woman, an elderly man and another man aged 55, all terminally ill and being taken from hospital to die at home with their families, La Repubblica reported.

The victims died from embolisms, caused when blood vessels are blocked – usually by a clot, a fat globule or an air bubble. More than 50 suspicious deaths involving Garofalo and two other stretcher-bearers are under investigation, the paper said.

The deaths – all involving patients from the Biancavilla hospital, about 18 miles (30km) from Catania in the east of the island – occurred over a four-year period beginning in 2012. None were originally thought suspect because the patients were all dying.

But the story came to light last year when a reformed mafioso turned informant told the satirical television programme Le Iene (the Hyenas) that the victims “did not die by the hand of God but for someone to earn €300”.

Since these were people “at the end of their lives who were going to die anyway, he injected air into their veins and they died of an embolism – so the family knew nothing”, the witness told the programme.

Garofalo then allegedly recommended the services of a funeral parlour, which grieving family members – “at a time of great sorrow and distress” – were only too grateful to accept. He later received a “gift” of €300, supposedly for dressing the bodies for burial.

The 28-year-old informant claimed mafia bosses “put the men on the ambulances”, and a part of the money “went to the Cosa Nostra” – specifically, according to prosecutors, to the Mazzaglia-Toscano-Tomasello and Santangelo clans.

The deputy prosecutor, Francesco Puleio, said the case revealed “appalling behaviours, including hastening the death of seriously ill people, people in a terminally ill state, for profit, for money, with total contempt for human life and dignity”.

The local police chief, Raffaele Covetti, said the the killings were “a particularly cruel way for these people to die”. Witnesses had only been prepared to talk because several clan members had already been jailed as part of a broader ongoing operation, he said.

Garofalo is also charged with complicity with the mafia as well as “acting with cruelty to people” and “committing a crime involving the abuse of a professional position”.