PARIS (AFP) - The father of a 33-year-old man of Moroccan descent who died while in police custody in France on Monday seized on President Nicolas Sarkozy's vacation in Morocco to appeal for justice for his son.

Mohammed Tais asked in a letter sent to Sarkozy and King Mohammed VI that the "truth about the circumstances surrounding my son's death be known" and that a new investigation be opened in the case dating back to 1993.

Pascal Tais was found dead in his holding cell on April 7, 1993 in a police station in Arcachon in southwest France where he had been taken after a brawl.

An autopsy found he had died of internal bleeding after his spleen ruptured and also had suffered from fractured ribs, a perforated lung and a head injury. His condition was also weakened from AIDS.

Several French courts have refused to order a new investigation into whether police were responsible for his death, but the European Court of Human Rights said in 2006 that there should be a new probe.

French government lawyers had argued before the rights court in Strasbourg that police had resorted to force to subdue Tais but that this was not the direct cause of his death.

Sarkozy and his wife Carla Bruni have been on holiday in Morocco for the past three days and joined the king for a dinner in their honour at his Marrakesh palace.

The French first couple are due to return to Paris on December 31.