High Court battle: What's £9 billion between brothers?

The return home of Brunei's controversial Playboy Prince could signal an end to a decade-long family feud. Cahal Milmo reports

The princes sitting cross-legged at prayers in a Brunei mosque last week would have passed unremarked but for one unusual and highly significant addition to the line-up. Alongside Sultan Hassanal Bolkiah, the dynastic billionaire who sits at the summit of the world's richest absolute monarchy, was his youngest brother, Prince Jefri.

Buried in the pages of the Borneo Bulletin newspaper, a photograph of the pious dignitaries was published alongside a 98-word description that listed the seven members of the Brunei royal family and carefully accorded "HRH Prince Jefri" his rank as the third most senior member of the Bolkiah dynasty.

To the uninitiated, it looked like a tedious court circular in an Asian sultanate whose oil wealth confers the fifth-highest GDP on the planet to a country the size of Norfolk.

In fact, it confirmed to Brunei's 375,000-strong population that the five-year exile of Prince Jefri from his homeland had ended – and that one of the most expensive and entertaining family feuds ever played out in London's High Court could be heading towards a resolution.

The presence of Prince Jefri, 55, in his brother's fabulously opulent palace is being interpreted as proof of a long-rumoured rapprochement between the two men after an 11-year legal battle over claims that the younger sibling misappropriated $14bn (£8.75bn) from Brunei's treasury while serving as finance minister and then failed to pay in full a £3bn settlement reached in 2000.

Largely fought out in the High Court at a cost of hundreds of millions of pounds, the dispute has laid bare toe-curling details of conspicuous consumption and questionable taste on the part of Prince Jefri, from a 50-metre yacht named Tits to a reputed penchant for jewelled watches that mark each passing hour with an image of a copulating couple.

Relations between the two royals reached their nadir last year when a High Court judge issued an arrest warrant against Jefri after he failed to appear at a hearing to explain how he had allegedly failed to disclose secret bank accounts and allowed funds to be taken out of other accounts previously frozen. Mr Justice Peter Smith warned it would take "an advocate of great skill" to persuade him not to remand the prince in custody.

But lawyers for Jefri this week signalled a thawing in relations with his brother, which could lead to a settlement to end a decade of rancour. David Sandy, of law firm Simmons & Simmons, said: "It's fair to say there's a much more constructive relationship between the parties. The discussions are continuing. I don't want to disrupt those by making any assumptions on the process other than that."

Having spent 12 months boltholed in Singapore, the arrival of Prince Jefri in Brunei, a former British colonial possession that sits on the northern coast of the Indonesian and Malaysian-administered island of Borneo, is all the remarkable given that he recently expressed concerns he would be charged with treason if he ever returned to his homeland.

The Bolkiah family can trace its status as Brunei's ruling family back to the 14th century. Despite some limited attempts at democratisation, Sultan Hassan, 63, retains control of an absolute monarchy he inherited when he took the throne in 1967. In a move that commentators suggested was linked to his dispute with Prince Jefri, the Sultan, who is also prime minister and defence minister, amended Brunei's constitution in 2006 to declare himself infallible, stating: "His Majesty the Sultan... can do no wrong in either his personal or any official capacity."

With a GDP of $20bn, half of which is earned through the country's oil and natural gas reserves, the Sultan has nonetheless been careful to ensure that his subjects receive a share of Brunei's wealth. The enclave offers each of its citizens free healthcare and education as well as subsidised food and housing. The government owns a ranch in Australia which is larger than Brunei itself and provides all the country's beef.

Prince Jefri, who had been close to his eldest brother, was placed in a position to cement this royal munificence when he was appointed minister of finance and head of the Brunei Investment Agency (BIA), the sovereign wealth fund set up to invest the country's oil earnings.

But the prince's sprawling programme of infrastructure projects and acquisitions abroad – from the Hotel Bel-Air in Los Angeles to the Queen's jeweller Asprey & Garrard, made through an investment vehicle called Amedeo – came to an abrupt end in the late 1990s. A financial crisis in Asia exposed alleged holes in the BIA's accounts and gave rise to allegations that the royal had embezzled £8bn to fund a personal spending spree that would have made the Lydian king Croesus blush.

Prince Jefri has consistently denied any wrongdoing and insisted much of the money he was accused of pilfering was, in fact, sent in "special transfers" to the Sultan's personal bank accounts.

Court documents nonetheless revealed that Jefri, inevitably dubbed the Playboy Prince, had an eye-popping capacity for dispensing cash. Spending at a rate of £500,000 a day for a decade, Prince Jefri allegedly acquired 2,000 cars, including Ferraris, Rolls Royces and Aston Martins; 17 aircraft, including a Boeing 747 adapted to transport his polo ponies and a Comanche attack helicopter; a vast portfolio of international property from London and Paris to New York and Singapore; and two speedboat tenders named Nipple I and Nipple II.

The deeply religious Sultan is no slouch himself when it comes to acquiring the trappings of wealth. His £4bn car collection is estimated to contain between 3,000 and 6,000 vehicles, including a 500-strong fleet of Rolls Royces – the largest in the world. He hired Michael Jackson to sing at his 50th birthday and gave a daughter – one of 12 children – an Airbus for her 18th birthday.

The feud looked to have reached a settlement in 2000 when Prince Jefri reached an out-of-court agreement with the BIA to return £3bn in assets. As part of the deal, the prince held an auction of his chattels from Amedeo's Brunei base, which included unused Mercedes Benz fire engines, two flight simulators, several hundred Louis XIV chairs and 16,000 tons of Italian marble.

But the deal proved to be one in a series of peaks and troughs in the relationship, with both parties subsequently trading High Court accusations of failure to keep their side of the bargain, including a £200m "lifestyle agreement" thrashed out between the two sides to keep Jefri in the manner to which he was accustomed.

In 2007, the Privy Council, which acts as Brunei's highest court, rejected Prince Jefri's final appeal against the 2000 agreement to return nearly all of his assets to BIA, apparently leaving him with a dwindling number of options. He has distanced himself from the accounts of his fast-living lifestyle, pointing that he only visited Tits half a dozen times, and prefers to cast the image of a besuited and serious-minded businessman caught up in an unfortunate family tiff.

A tone of contrition has since entered into the prince's public stance, despite his continued insistence that he has been used as a sacrificial lamb to disguise the wider profligacy of Brunei's rulers. Speaking last year, he said he had made mistakes "for which I am truly sorry", before adding: "I am no angel, for sure, but I have been the fall guy."

If the return of Prince Jefri does turn out to be the precursor to a burying of hatchets, it is likely the only tears to be shed will come from the circle of top London legal firms who have represented each party through dozens of hearings in Britain and Brunei. So far, the case is estimated to have earned the capital's barristers and solicitors anywhere between £250m and £500m.