Italy's foreign minister has denied reports that Italy paid $12 million in ransom money to free two young aid workers held for months in Syria.

Hours after 21-year-old Greta Ramelli and 20-year-old Vanessa Marzullo landed in Rome, Paolo Gentiloni told lawmakers the reports "were void of any basis in reality and in some cases spread by terrorists".

Dubai-based broadcaster Al Aan reported that Italy paid $12 million, sparking debate in Italy about ransom payments and drawing harsh words from opposition politicians.

Mr Gentiloni told the lower house that Italy is "against payment of ransom" and follows "the rules and behaviours" shared by the international community.

The women were kidnapped on July 31 on their third visit to the country.