Reggio Calabria, March 8 - A envelope containing gunpowder addressed to a top anti-Mafia prosecutor in the 'Ndrangheta mafia-plagued city of Reggio Calabria was intercepted Friday in the city's main mail-sorting office. The envelope sent to Giuseppe Lombardo also contained the message: "If you don't stop it, another 200 kilogrammes are ready". Police said Lombardo was leading some of the "most delicate" investigations into the city's 'Ndrangheta clans, considered the most powerful in Calabria. He is probing suspected links between the crime families and "criminal elements in the institutions, politics, business and free-masonry," they said. 'Ndrangheta is Italy's most powerful and dangerous mafia, investigators say, and has invested its huge cocaine profits in affluent northern Italy and other countries.