Intertanko and Intermanager have joined the chorus against the two-year jail sentence handed down to Captain Mangouras by the Spanish Supreme court for the Prestige casualty in 2002.

In a statement Intertanko said: “Captain Mangouras, now 81 years old, is outrageously branded a ‘reckless’ criminal. Yet his actions were described as ‘exemplary’ by the vessel’s flag state.” The Spanish authorities refused to allow the Prestige into port after it was damaged in a storm and the vessel eventually split in two and sank 250 miles off the Spanish coast.

The tanker owner’s representative body went on to call the verdict “unjustifiable” and “fundamentally wrong”.

“This sets a deplorable precedent,” said Katharina Stanzel, md of Internanko. “Are ships' masters who exercise best professional judgement in impossible circumstances to be shamefully treated as criminals?”

Meanwhile ship manager association Intermanager described the verdict as “deplorable”.

Gerardo Borromeo, president of InterManager, said he was hugely disappointed by the court ruling and said it set a very worrying precedent as far as the role and responsibility for Masters in certain jurisdictions.