ROME (AP) — Anti-Mafia prosecutors are investigating the slaying in Italy of a brother of a turncoat from an 'ndrangheta crime clan family.

The man was gunned down by two masked attackers on Christmas near his home in the Adriatic beach town of Pesaro.

Italian news reports said the attackers fired around 20 bullets, killing 51-year-old Marcello Bruzzese. From Calabria, the 'ndrangheta's power base, he was the brother of Girolamo Bruzzese, whom Italian news reports said began collaborating with authorities in 2003.

On Wednesday, some questioned if the victim had adequate protection from the government. Turncoat testimony has been a key weapon against the powerful 'ndrangheta and other Italian organized crime groups.

Libera, an anti-Mafia advocacy group, said the ferocious slaying "raises many questions about the protection system for collaborators and their families."