Updated

The founder of a Spanish aid group that rescues migrants in the Mediterranean says Italian authorities have released his organization's ship after impounding it for taking 218 migrants to Italy.

Proactiva Open Arms founder Oscar Camps says in a tweet Monday that the ship is free to leave the Sicilian port of Pozzallo. But he says Italy is still investigating whether the group should face charges of criminal association and aiding illegal immigration.

Proactiva's Italian lawyer Rosa Lo Faro confirmed the judge's decision.

The investigation stems from a tense high-seas standoff last month between the Open Arms crew and the Libyan coast guard. The group refused to relinquish the migrants they had picked up in international waters and took them to Italy, where authorities are trying to stem migration.