The appeal, which the officials said was lodged on Thursday, should come to court in the coming weeks, Fabrice Dubest, a defence lawyer for Dodi’s father, Mohamed al Fayed, added.
That means it could coincide with a January British inquest into the death of Diana, who was killed with her friend Dodi and their chauffeur Henri Paul when their Mercedes crashed in a tunnel as it sped away from the Ritz hotel in Paris.
“The Paris prosecutor first waited to see whether Mohamed al Fayed would appeal or not. He lodged an appeal at the end of November. The prosecutor decided at the beginning of December to follow,” Dubest told Reuters on Friday.
“The case will be brought before the court of appeal in the coming weeks, and will be completely re-examined,” he said.
A Paris court ruled that Christian Martinez, Fabrice Chassery and Jacques Langevin did not break privacy laws when they photographed Diana and Dodi on August 31, 1997, the night their car was chased through Paris by paparazzi on motorbikes.
Martinez, of the Angeli agency, and freelancer Chassery took photos of the couple as they lay in their crumpled Mercedes.
Langevin, who worked for the Sygma agency, had taken shots of them before the crash as they left the Ritz hotel.
None of the pictures in question have been published.
The court said photos taken outside the Ritz did not breach privacy because no “intimate gestures” were caught on camera, and noted that Dodi and Diana were aware of being photographed.
Of those taken at the accident scene, it noted the doors of the Mercedes were open and said a crashed car on a public road was not a private sphere requiring permission to enter.
Evidence at the initial inquiry stated that the driver was drunk at the time of the accident, something his parents reject.
Mohamed al Fayed has repeatedly called for a British inquiry into the incident, insisting Diana and his son were murdered by the secret services. He has also called for paparazzi to be punished for their role in the crash.
After failures so far in French and English courts, al Fayed is trying to get Scottish courts to take up the matter, saying earlier this week: “This is not only my son but the most famous, most loved woman in the world”.