A battle of wills: Gayatri Devi's £250m legacy

She was once named by Vogue magazine as one of the world's 10 most beautiful women, the third wife of a Rajasthan prince who counted British royalty and Jackie Onassis among her friends. During the summer months that she spent every year in London's Knightsbridge she would mingle with aristocracy, while back home in India's "pink city", she would host parties on her lawn for the likes of Mick Jagger and Michael Caine.

But the death of Gayatri Devi, the third wife of the last official Maharajah of Jaipur, has reignited a bitter dispute in the royal family over assets worth perhaps £250m which include fabulous palaces, jewels and paintings. It is a fight that has pitched grandson against step-uncle and half-brother against half-brother – an unseemly row that has reverberated around this desert city where she lived a life in the style of another age.

The dispute within the Jaipur royal family is extraordinarily labyrinthine and multi-layered, but in its essence it pitches Gayatri Devi's grandchildren against two of her step-children.

The grandchildren, Devraj Singh and Lalitya Kumari, grew up in Thailand but late last year returned to Jaipur, smoothed over any differences they may have had with their grandmother and were present – so they claim – when she produced a will that left all her assets to them. Previously, two step-uncles of the grandchildren, Prithviraj and Jai Singh, had produced a will that they claimed left everything to them.

Until now, most parties have chosen not publicly to air their grievances, but in his first interview, Gayatri Devi's grandson told The Independent he believes his step-uncle Prithviraj has actively worked against him. "I think he would rather I was not here," Devraj said, sitting on a cream silk sofa at Lilypool, the French-style bungalow in Jaipur that his grandmother and grandfather built. "There is a lot for him to gain if I am not around."

He said the ill-feeling of his step-uncle, who had once acted as his grandmother's executor, had even extended to two fabulous vehicles once owned by his father and grandmother that were currently sitting in a shed. Throwing back the dust-covers on a baby-blue Bentley believed to have been built in the 1920s, and a 1949 Jaguar sports car he shrugged: "My uncle has the keys to these."

Gayatri Devi was born into the royal family of Cooch Behar, one of around 560 "princely states" that existed in India. She was just 12 when she first met the then-21-year-old Maharaja of Jaipur, the urbane, polo-playing Sawai Man Singh II. The prince already had two wives, both essentially for political reasons, but in 1940 the pair shocked blue-blooded society by announcing their plans to marry. The Maharajah had four children by his first two wives, and with his third wife, he produced a son, Jagat.

If the Maharani, as she was commonly known, had caused shockwaves by the manner in which she got married, there was further surprise when she formed the anti-Congress Swatantra Party and successfully ran for parliament in 1962, 1967 and lastly in 1971, a year after the death of her husband following a polo accident.

When India's Prime Minister Indira Gandhi announced that royal privileges and titles afforded to the hundreds of Indian princes were to be officially scrapped, Gayatri Devi was accused of tax evasion and emergency powers were used to send her to Delhi's notorious Tihar jail.

It was often said the socialist Prime Minister was jealous of the royal politician, and once referred to her as a "bitch and a glass doll" in parliament. During the five months the Maharani spent in prison, she continued to wear chiffon saris, jewellery and perfume and is said to have borne herself with grace. "It wasn't too bad," she once cheerfully told an interviewer. "In Tihar, I had my own bedroom with a veranda and my own bathroom. We were well looked after, except we were not free." On her release from prison, she decided to quit politics.

By the time the Maharani's son, Jagat, died from alcoholism in 1997, he had long been estranged from his Thai wife and two children, Devraj, 28, and Lalitya, 30, who had grown up in Bangkok. With her son and grandchildren absent, Gayatri Devi looked to two of her three step-sons for support.

Whether or not her natural son Jagat left a will is unclear, but in 2006 Devraj filed a lawsuit in India claiming that his father's shares in two grand hotels in Jaipur had been "diluted" by his step-uncle, Prithviraj. The shares at the Jai Mahal Palace had been reduced from 99 per cent to just 7 per cent, while Prithviraj's shares had increased to 93 per cent. In regard to the Rambagh Palace Hotel, the shares had been reduced from 27 per cent to 4 per cent. The grandchildren claimed they had lost more than $50m.

The case has not yet been settled and Prithviraj has declined to comment on the matter. Confronted at his office in the grounds of the Rambagh Palace Hotel, he would only say: "A lot of what has been written in the media is not true." Subsequent attempts to speak with him were unsuccessful.

This summer, as speculation grew in the Indian media over who would inherit the assets of the woman who had once shot tigers with Queen Elizabeth and Prince Philip, Devraj and his sister called a somewhat peculiar press conference at which they announced they were the sole heirs but declined to answer questions.

Now, sitting surrounded by black-and-white photographs of his grandmother, Devraj says the will was signed by her in May of this year, in the presence of a third step-uncle, Bhawani Singh, who, as Man Singh's eldest son, inherited the title of Maharajah of Jaipur. He declined to produce the will, apparently on the advice of his lawyer, but insisted that his grandmother had been in a fit state of mind when it was signed.

"I think that [Prithviraj was] surprised by that last will. There was a time when there was a rift between ourselves and her. Everyone was surprised by her last move, not just the uncles," he said, saying he had visited his grandmother in hospital just days before her death in July. "She was not the typical sweet old grandmother. She had her charms, but her will had to be obeyed. She could be very kind and caring but sometimes, if you did not please her, she could be quite nasty."

Of the rift with his step-uncles Prithviraj and Jai, who had once been seen as allies of Gayatri Devi, he said: "I was hoping that we could settle these differences by talking round them rather than having to go to court. We have not been able to reach that stage yet... The end of an era for our family was with the death of my grandfather in 1970 and since then, for each branch of the family, the survival instinct has been to get as many resources as possible. That leads to collective downfall."

Bhawani Singh, a former military officer still generally referred to as His Highness, lives in a part of Jaipur's splendid 18th-century City Palace that is roped off from the crowds of tourists. The Maharajah, attended to by servants dressed in white tunics and bright red turbans, recently suffered a stroke that left him with difficulty speaking.

Yet he confirmed that he was trying to resolve the issues within the family. "Too early [to say]," he replied, when asked what progress he was making. Asked what he was trying to achieve for the various factions of the royal family, he said simply: "Peace."

When Gayatri Devi was cremated with state honours this summer in a special funeral ground reserved for former queens of Rajasthan, two elephants led the cortège. Among the people they once ruled over, the Jaipur royalty appears to attract a fair degree of enduring good will – the legacy, perhaps, of projects such as the establishment of schools and health clinics that was started by the Maharani and continued by her grandson.

Yet not everyone is impressed by the royal rancour over who should inherit her wealth. One Jaipur resident, who asked not to be identified, said: "I think it's terrible. They all have so much money and they're fighting about getting more. And no one is benefiting from that money. I think the government ought to take it."