Some 50 people were arrested in Italy today and another 150 were under investigation as part of a European-wide operation against money laundering, police said.
Police said the operation involved members of the Russian mafia as well as Italian and foreign businessmen with suspected connections to organised crime.
A statement said German, French, Monte Carlo and Swiss police, together with the FBI, were involved in the investigation.
More details were due to be disclosed at a news conference later today.