Over 40 people were arrested in Palermo after investigators discovered hard-up victims were having their arms or legs broken in exchange for a small part of the pay-out from insurers, police said on Monday.
Those in on the fraud included false witnesses to the accidents, doctors providing fake medical reports, physiotherapy centres certifying care that was never provided, and a lawyer filing the claims, police said.
The victims were "people on the margins of society... drug addicts, alcoholics and the mentally ill".
They were promised a cut of the insurance pay-out, but took home as little as 300 euros.
The gang broke upper or lower limbs - referred to in code as the "first floor" and "ground floor" - by throwing cast-iron body-building weights at their victims or beating them with iron bars, police said.
Police first uncovered the scam in 2017 after the death of a Tunisian man who initially appeared to have died in a road accident, but was discovered during the autopsy to have had a heart attack after a beating.
He had been given crack cocaine to minimise the pain.
Eleven people were arrested in a first operation against two other gangs in Sicily last August, and three of them turned state witness, leading police to investigate some 250 suspects.
Around 60 attacks were uncovered in wiretaps, with the criminals preferring to target teenage single mothers because the payouts were bigger.
The victims were taken to isolated apartments or warehouses, and given mild painkillers or ice packs to numb their limbs.
The arms or legs were suspended between blocks of concrete and a bag of ron weights or large stones were thrown at them to fracture them, police said.
Multiple fractures were "better" because they were subject to larger payouts.
Five of those arrested Monday specialised in the bone breaking, according to the Giornale di Sicilia local daily, including one dubbed "Tony the Meek".
The head of one of the gangs drove a luxury car and owned a speedboat, reports said.
The road "accidents" were staged in areas not covered by video surveillance cameras. Gang members would then pose in hospital as the victims' relatives, to ensure they stuck to the story.