A wave of deaths in Sicilian hospitals has highlighted a crisis in the island's health service, linked by a senior politician to the draining of public funds by the mafia.

Three suspicious deaths of patients in three days over Christmas have raised alarm. A 78-year-old woman died of a heart attack in a Palermo emergency ward on December 28 after waiting four hours to be seen. The ward has no triage, or system for prioritising patients.

Earlier, a pregnant woman delivered a stillborn child after doctors declined to carry out a caesarean section, while the parents of a newborn son who died in hospital have accused doctors of malpractice.

"Cosa Nostra is investing heavily in private health centres in Sicily which are subsidised by the state," said Francesco Forgione, the head of Italy's parliamentary anti-mafia commission.

After drug trafficking, the control of public and private contracting is the second most lucrative activity for organised crime in Italy, amounting to a turnover of about €17.5bn (£11.8bn), of which the Sicilian mafia is responsible for €6.5bn.

Sicily has about 1,800 private health centres compared with 150 in the rich northern region of Lombardy, said Mr Forgione. Such clinics offer government-subsidised services in order to reduce the workload for public hospitals. "But that has diverted funds from public hospitals, which are falling into a state of disrepair," he said. "Sicily is the first region in Italy for the financing of private health centres and the first for patient deaths."

Mr Forgione, who was appointed to head the anti-mafia commission by the centre-left government of Romano Prodi, has said that investigating mafia penetration of the health business will be a priority in Sicily and Calabria. In 2005 Francesco Fortugno, number two in the regional assembly, was murdered by the 'Ndrangheta crime syndicate while investigating the awarding of hospital contracts.

In Sicily, the mafia is not only investing in private clinics but is also involved in steering public health contracts towards friendly companies, said Mr Forgione. "During the hunt for mafia boss Bernardo Provenzano it was even discovered that some Palermo neighbourhood bosses were themselves doctors or lawyers, part of a new mafia bourgeoisie."

Giuseppe Guttadauro, the jailed boss of Palermo's Brancaccio district, was a high profile surgeon. Police listened in as Guttadauro discussed political appointments with the city's public health assessor Domenico Miceli, himself a doctor. Miceli was in turn sentenced to eight years for mafia association in December.

As the Sicilian mafia moves into low key businesses like healthcare, a more traditional Cosa Nostra calling card has however recently resurfaced in Sicily. A severed goat's head was delivered to Rino Foschi, sport director of Palermo football club, on December 22, possibly as a protest against a clampdown on the free distribution of tickets to games. The city's cultural assessor also received a goat's head.