An Italian-led probe of a suspected international child pornography ring led to the arrest of an Italian man and to raids on 40 houses in Italy, Romania, Slovenia and Switzerland on Thursday, officials said.

Forty people were being investigated, including 25 in Italy, said Capt. Luigi Mancuso of the paramilitary Carabinieri police in Rome. He said the Italian, a 60-year-old resident of Rome, was arrested because he distributed pornographic material as well as downloaded it.

Europol, which assists in coordinating international police operations, said in a statement that the probe involved an "Internet (message) board whose members possessed and distributed child sexual abuse material." The network allegedly operated by posting illegal images to the free board in encrypted formats for short periods of time, it said.

Europol Director Max-Peter Ratzel said in the statement that the operation "stopped yet another circle of criminals perpetrating one of the most devastating and appalling types of crimes."

Police in Italy said they shut down an Italian Web site that had been contacted by 2,707 people across the world. The operation, launched and led by the Rome Carabinieri, started in March 2006.

Click here for more Europe stories on FOXNews.com.