Wartime collaborator Maurice Papon took his case to a French appeals court on Wednesday, demanding to be freed on the grounds of old age and poor health.

But the French state prosecutor insisted at the closed-door hearing that releasing Papon would be a threat to public order, and said he had been convicted of crimes of "exceptional seriousness".

Papon, 92, was jailed for 10 years in 1999 for signing World War II orders which led to the deportation of more than 1,500 Jews.

Maurice Papon should be treated just like anyone else

Jean-Marc Varaut Papon's lawyer

He was convicted of complicity in crimes against humanity.

The appeals court is expected to give its decision on 18 September.

A separate appeal against the conviction itself is still being prepared, after the European Court of Human Rights backed Papon's right to appeal in July.

The attempt to free him on health grounds has been proceeding in a parallel legal battle.

He is seeking freedom under a new French law which says prisoners should be freed if two independent doctors agree their health is endangered by remaining behind bars.

Bed-ridden

Papon has a pacemaker and a history of heart problems, and doctors have testified that he is bed-ridden and "practically totally incapacitated".

But his attempt to win release under the law was refused by a judge in July, on the grounds that Papon had refused to offer compensation to the families of his victims, and had therefore failed to demonstrate "commitment to social rehabilitation".

Papon is now appealing against this decision. He did not attend Wednesday's hearing.

President Jacques Chirac has repeatedly refused to pardon Papon, who signed the deportation orders while a police chief in Bordeaux region.

Papon is France's only surviving convict from World War II. He is held in Paris's Sante prison.

Papon's lawyer denies his client poses a threat to public order

Papon's lawyer, Jean-Marc Varaut, denied the state prosecutor's claims that freeing the collaborator would be a threat to public order. He said the issue "does not figure in law".

"Maurice Papon should be treated just like anyone else," he said. "Every man has the same human rights as everyone else... That's what we confidently expect the court to decide."

Papon's lawyers have also insisted that the judge at the first hearing was wrong to claim Papon would not compensate the families.

"Papon has already paid some money to the victims to the tune of hundreds of thousands of francs. I do not see how the appeal court can confirm the judge's conclusions when these are so clearly incredible," said Francis Vuillemin.