The US captain of a P&O cruise ship found to be burning fuel with excessive sulphur levels was fined €100,000 (£88,000) in a Marseille court on Monday, the first such ruling in France.

The prosecution was intended by authorities to signal a new intent to tackle pollution from cruise ships after a spot check in March on the Azura, operated by P&O Cruises, found it contained unauthorised bunker fuel.

The case has shone a spotlight on practices in the multi-billion-euro cruise industry, with prosecutor Franck Lagier saying P&O "wanted to save money at the expense of everyone's lungs".

Captain Evans Hoyt knew the fuel was illegal - it contained 1.68 percent sulphur, surpassing the 1.5-percent European limit, Mr Lagier said during the trial.

The judge handed Mr Hoyt, 58, a fine of €100,000 , but specified that P&O's parent company, US-based cruise giant Carnival, should pay €80,000 of the sum.

Bunker fuel, also known as heavy fuel oil, is one of the most polluting transportation fuels and is high in sulphur, which when burnt can cause respiratory problems and acid rain.

Regulations on the amount of sulphur authorised vary internationally, with ultra-clean fuel mandated in areas such as the North Sea and Baltic Sea in Europe, as well as around North American ports.