Around 250 officers took part in the huge operation which included the arrest of Giuseppe Casamonica – one of the alleged bosses of the syndicate, local media reports.
As well as the raids in Rome, properties were busted in the towns of Reggio Calabria and Cosenza in the south of the country close to Sicily.
Cops found $60,000 in cash, bank accounts, luxury watches and cars.
Spada, who fought over 40 pro fights at middleweight, had his gym in Rome seized and shut down.
Prosecutor Michele Prestipino said: “They didn’t need to use violence, the Casamonica name was enough.”
Cops have issued warrants for six alleged mobsters who are still believed to be on the run.
In a raid on the Casamonica crew in 2010, police seized $11.5 million worth of assets including cars, properties and land.