Christie's, the auction house, has become embroiled in one of Indian royalty’s most bitter family feuds over the sale of the Baroda Pearls, a necklace valued at more than £5m.

The auctioneer, which is billing the Maharajah of Baroda’s pearls as “legendary” and “the most important pearl necklace in the world”, is going ahead despite threats of legal action from the maharajah’s family.

The pearls are part of the late Maharajah Fatehsinh Gaekwad’s disputed estate, estimated at between £750m and £1 billion. It includes the Laxmi Vilas Palace, set in 700 acres of farmland in Rajasthan, and a palace in Bombay.

The dispute began in 1989 after the maharajah died childless and intestate, leaving his brothers, Ranjitsinh and Sangramsinh, to fight over the palaces, land, investment companies and a huge array of jewellery.

The collection has been celebrated throughout Europe, India and the Arab world for centuries, but were most famously worn by Maharani Sita Devi, a scarlet woman of Indian royalty who became known known as the subcontinent’s “Mrs Simpson”.

In 1943 she became the second wife of Sir Pratapsinh Gaekwad, Fatehsinh’s predecessor, and swiftly moved much of the collection to bank vaults in Europe and her home in the south of France. She often wore the pearls in public.

They included the Pearl Carpet, which was made of diamonds, rubies and emeralds as well as pearls. It was commissioned by Maharajah Khande Gaekwad in the 1860s as a gift to be draped over the shrine of the Prophet Muhammad in Medina. It was never delivered, and was shipped to Europe, where it was sold to an unknown buyer.

The collection also included the Baroda Pearls, originally a seven-string necklace, the 128-carat Star of the South diamond, which was sold to Cartier in 2002, and the Moon of Baroda, a 24-carat diamond worn by Marilyn Monroe in the film Gentlemen Prefer Blondes.

The Baroda Pearls, now 68 pearls in two strings, are due to be auctioned on April 25 with other pieces from the collection at Christie’s in New York as part of its Magnificent Jewels sale.

Last night Kailash Jethmalani, a lawyer for the late maharajah’s younger brother Sangramsinh, said he was considering legal action to halt the sale, which he claimed was in breach of Indian heritage laws and a court order banning the disposal of the Baroda estate until the family’s long-running dispute was resolved.

Since 1989 legal actions between family members have been bogged down in India’s notoriously sluggish courts.

Last week Jethmalani said once again Ranjitsinh, the current maharajah, was trying to sell India’s heritage to the highest bidder. “He’s selling off everything so there’s nothing left to share at any level,” he claimed.

A spokeswoman for Christie’s said it was satisfied the pearls were legally acquired and exported to New York.

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