ROME (AFP) - The ferry that caught fire in the Adriatic passed a recent technical inspection after a repair to a faulty fire door, its Italian owner said Sunday.

Carlo Visentini, the chief executive of the Visenti Group, which owns the boat, said checks had been made on Dec 19 in the Greek port of Patras and the minor flaws revealed had been addressed.

"The tests confirmed that the boat was in full working order," Visentini was quoted as saying by Italian news agency ANSA.

"The inspectors did uncover a slight malfunction in one of the fire doors, number 112, situated on bridge number 5, the one where, according to the information we have so far, the fire developed," he added.

"This was immediately repaired to the satisfaction of the inspectors and therefore the boat was able to continue in service." It remained unclear Sunday how the fire on the ship, which had been leased to Greek ferry operator ANEK Lines, started.

An Italian-led rescue effort was continuing into the night with hundreds of passengers and crew still on board the stricken vessel.