Seamen go on trial Tuesday over the sinking of the Prestige petrol tanker which spilt a devastating oil slick when it sank off Spain in 2002, with hundreds of plaintiffs seeking billions in damages.

Authorities have set up a court in an exhibition centre for the huge trial in the northern city of A Coruna, which environmentalists say does not go far enough in seeking justice for Spain's worst oil slick and preventing such a disaster occurring again.

Apostolos Mangouras, 78, the Prestige's Greek captain, is charged alongside two other officers and a Spanish official over the disaster, which saw miles of beach in Spain, Portugal and France choked by oil.

Prosecutors are demanding 12 years' jail for Mangouras, who is charged with harming the environment along with Greek chief engineer Nikolaos Argyropoulos and first mate Irineo Maloto, a Filipino who has not been apprehended.

The fourth defendant is Jose Luis Lopez-Sors, head of the Spanish merchant navy at the time, who ordered the ship out to sea when it was losing fuel.

"The total demand for damages is more than 2.2 billion euros," a court official said, adding that there are 55 separate cases being brought by some 1,500 plaintiffs.

The total cost of the environmental damage wrought by the oil slick has been calculated at more than four billion euros, most of it for the Spanish state.

The Prestige leaked 50,000 tonnes of fuel into the Atlantic after it sank off northern Spain. It took on water in a storm on November 13, 2002, and drifted for six days before breaking up and sinking.

Over the weeks that followed, the vast oil slick engulfed thousands of kilometres (miles) of coastline, prompting 300,000 volunteers from around Europe to come and clean it up.

Environmental groups complained that key people responsible for the disaster were not being tried and warned that the lessons from the disaster had not been learnt.

"There will clearly be people missing from the dock," said Jaime Doreste, a lawyer for the Spanish non-government group Environmentalists in Action.

"They could have been much more ambitious with the prosecutions," he added.

"Lopez-Sors did not act unilaterally. The chain of decision-making went up to higher political officials."

He said charges should be brought against ABS, the marine classification company that certified the Prestige as seaworthy, and complained that such single-hull tankers are still being used to transport petrol.

Doreste warned that the full health and environmental effects of the oil slick had not been made public.

A study published by Spanish researchers in 2010 said fishermen that participated in the clean-up suffered genetic and lung problems.

"We are shouting: never again," said Theo Oberhuber, a campaign leader of Environmentalists in Action.

"We are wondering when measures will be taken that will really prevent this from happening again."

After three days of procedural matters this week, the defendants are due to make their first appearance in the trial on November 13, the 10th anniversary of the disaster.

The trial is due to last until May 2013 and will hear testimony from 133 witnesses and 100 experts, the court said.