An inquest into the death of Princess Diana opened on Tuesday, 10 years after she was killed in a Paris car crash, with her lover’s father convinced that the British royal family ordered the killing.

Mohamed al-Fayed, whose son Dodi died in the crash after a much-publicised summer romance with the “people’s princess”, alleges the couple were killed on the orders of Queen Elizabeth’s husband, Diana’s former father-in-law.

Al-Fayed, owner of London’s luxury Harrods store, fought a long legal battle to have the inquest heard by a judge and jury. London’s High Court is expected to spend up to six months deciding if her death was an accident.

“Mohamed al-Fayed has maintained throughout that the crash was not an accident, but murder in furtherance of a conspiracy by the Establishment, in particular his Royal Highness Prince Philip, the Duke of Edinburgh, who used the security services to carry it out,” judge Lord Justice Scott Baker said.

Major probes by the police have concluded the deaths were an accident caused by a speeding chauffeur, who was found to be drunk.