Turkish President Recep Tayyip Erdogan says an Italian criminal investigation involving his son could complicate relations with Rome. Italy's premier dismissed the comments, saying that Italian judges don't respond to the Turkish leader.

Erdogan's son Bilal is under investigation for alleged money-laundering in Bologna, where he moved last year with his family. Erdogan told RAI News 24 Tuesday that the probe "could put our relations with Italy in difficulty" and added that Italy should instead concentrate on the Mafia.

Italian Premier Matteo Renzi responded with a message on Twitter, saying: "In this country, judges respond to the law and the Italian constitution, not to the Turkish president."

Foreign Minister Paolo Gentiloni said that magistrates and law enforcement were fully engaged in fighting the Mafia "and don't need any one's encouragement."