Somali pirates have received a $4m ransom to free an Italian tugboat that was seized four months ago, one of the pirates has reportedly told Reuters.

But Italian Foreign Minister Franco Frattini has denied any ransom was paid, saying the Somali prime minister had personally intervened to secure the release of the ship.

The owners of the Buccaneer, Ravenna-based Micoperi Marine Contractors, said on Sunday the ship was not freed as a result of military action or ransom payment, said Reuters.

“No ransom has been paid, the pressure on the pirates was enough to make them retreat,” Reuters said, quoting Frattini.

East African Seafarers’ Assistance Program regional maritime group coordinator Andrew Mwangura said the pirates received $5m.

Crewed by 16, the Buccaneer was hijacked on 11 April in the Gulf of Aden along with two barges.