The discovery of a mysterious deathbed will has reopened the fight for a £50 million fortune left by a former empress of Iran who died in Paris two years ago.

Soraya Esfandiary Bakhtiary, who was married to the Shah of Iran for seven years in the 1950s, was tagged the Sad Queen after being banished from his court for failing to bear him an heir.

On her death in October 2001, she left her haul of jewellery, fine art, furs and a Rolls-Royce to her brother, Prince Bijan Bakhtiary, but he survived his sister for just eight days.

Prince Bijan, an enfeebled opium and alcohol addict who had lived in Cologne, in Germany, for decades, was warned that he was too ill to travel to Paris for the funeral but ignored his doctors’ advice.

He died of heart failure in a room at the George V hotel in Paris, apparently intestate and without a natural heir, prompting an unseemly clamour of bogus claimants for his fortune.

More than 50 people claimed to be related to the empress and the prince but the state of North Rhine-Westfalia, of which Cologne is the capital, emerged as the most likely beneficiary.

In a dramatic development last week, however, a court dealing with the case revealed the existence of a slip of paper purporting to be Prince Bijan’s “last will”.

Allegedly scribbled down by the prince only five hours before he died, it names Hassan Firouzfar — an Iranian who worked as the prince’s private secretary — as the sole beneficiary.

“Mr Hassan Firouzfar, saviour number one and my only friend, I name him as my sole inheritor,” the document states. Firouzfar was present when the “will” was allegedly dictated.

Birgit Niepmann, a spokesman for the Cologne civil court, said last week: “If the will proves to be genuine, the whole lot will go to Mr Firouzfar. We are already having to cope with legal action from the other claimants who insist that the will has been faked.”

In an effort to establish whether the will is genuine, the court has called in a doctor, a psychiatrist and a handwriting expert. Officials are preparing to sift through 2,000 pages of evidence submitted by people claiming to be relations of Soraya before they are able to reach a judgment.