Florence, May 30 - A slew of businesses owned by Chinese immigrants in Italy are alleged to have illegally sent 4.5 billion euros home between 2006 and 2010, Italian police said Thursday. Florentine prosecutors said they had informed 287 immigrants, "almost all Chinese", that they had ended a tax-evasion and money-laundering probe into them, and 24 are facing possible charges of mafia conspiracy. The suspects allegedly used money-transfer agencies to dodge controls, never sending more than the 2,000-euro limit at which checks are triggered, and sometimes sending cents, police said. Police called it a "huge money-laundering operation". The suspects, resident in cities with large Chinese communities like Rome, Padua, and Prato north of Florence, allegedly made the money off the books and often by exploiting co-nationals on illegally low wages, police said.