It’s a divorce battle that pitches Moscow against London, involving tax havens, sumptuous properties, a mega-yacht and priceless art. Now, the acrimonious row between Farkhad Akhmedov, a Putin ally and oligarch, and his former wife has taken a new, rancorous twist.

After more than three years fighting a high court ruling ordering Akhmedov to pay Tatiana Akhmedova, who is British, hundreds of millions of pounds, his lawyers have involved the international police agency Interpol in their attempts to stop her from seizing his assets. The highly unusual development has triggered claims that Akhmedov’s lawyers are abusing the legal process, claims that have been strongly rejected.

The eye-popping divorce row went public in 2017, a year after Akhmedov, who made more than £1bn in the oil and gas trade, was ordered to pay Akhmedova £453m in the UK’s largest-ever divorce settlement. Since then, he has been accused of hiding his assets and cash overseas as he continues to dispute the ruling.

Lawyers acting for Akhmedov, who was born in Azerbaijan but has indefinite leave to remain in the UK, argued that he had made a “stellar” contribution to his wealth creation, which meant that he should not have to give his wife, a British citizen since 2000, almost half of his fortune. Crucial to Akhmedov’s defence was the claim that an earlier divorce between the couple – in Moscow 19 years ago – supersedes the UK judgment, making his ex-wife’s attempts to seize his assets a fraudulent act.

However, handing down his judgment in 2016, Justice Haddon-Cave said he had found no evidence of the earlier divorce. “The inference to be drawn … is that the 2000 Moscow divorce documents … were, at all material times, forged,” Haddon-Cave concluded.

Luna, the £230m yacht bought from Roman Abramovich, on the French Riviera. Photograph: Action Press/REX

Haddon-Cave ordered that a raft of Akhmedov’s assets should be frozen. These included several offshore bank accounts, a collection of vintage shotguns, a £350,000 Aston Martin and a modern art collection, estimated to be worth £90m and which includes Mark Rothko’s Yellow and Blue and Damien Hirst’s Kingdom of Heaven.

But Akhmedov’s lawyers continue to reject the British ruling, insisting to the Russian authorities that the 2000 divorce was genuine.

Documents seen by the Observer show that last June, in response to requests from Interpol Lichtenstein, Interpol Russia confirmed that the couple’s marriage had been dissolved “in accordance with the decision of Zyuzinskiy district Court of Moscow dated 18.08.2000”.

Moreover, Interpol Russia informed Interpol Lichtenstein that it was investigating claims from Akhmedov and his lawyers regarding the “misappropriation” of his assets on a “large scale”, based on a “fraud” committed by his ex-wife.

The involvement of Interpol Russia in the divorce row was condemned by Yury Kuznetsov, Akhmedova’s lawyer in Moscow.

“By the time the documents were passed to the Russian authorities, the English court had already concluded that their substance had been falsified. I am not aware of any explanation for this conduct and am disturbed by this as it appears to me that Mr Akhmedov – or someone on his behalf – was seeking to mislead Russian Interpol in an attempt to suborn Russia’s legal processes.”

Hannes Arnold, Akhmedova’s lawyer in Liechtenstein, added: “It is unfortunate that Interpol Russia has been misled into passing along indisputably distorted information in response to the request of the Liechtenstein criminal authorities on the proceedings in Russia, which is clearly not in compliance with the facts. The suspicion of abuse of Interpol Russia by Mr Akhmedov – or someone on his behalf – is obvious.”

But a spokesman for Akhmedov, who last year appeared on the “Putin List,” an inventory compiled by the US authorities of business and political elites with close ties to the Kremlin, denied the suggestion that Interpol was being used in an abuse of the legal process.

“Interpol was asked by a Liechtenstein judge to investigate the whereabouts of critical Russian court documents relating to the 2000 Moscow divorce,” the spokesman said.

“Mr Akhmedov’s legal team told Interpol – as they had previously told the courts – that the documents were criminally destroyed by agents acting for Tatiana. A ruling is awaited from the Russian supreme court in the matter.”

The extraordinary case has shone a light on the rarefied world of Russia’s super-rich. The court heard that Akhmedov had bought two of his sons multimillion pound properties in London and that his ex-wife required £30m to buy a foreign property and £40m for a residence in England. She also needed annual income of around £5m to maintain her current lifestyle.

The court heard that Akhmedov’s wealth resided largely in a Bermudian trust that had links to companies in Panama, Cyprus and the Isle of Man.

His ex-wife’s case is being supported by Burford Capital, a boutique finance company that provides funding for high-net-worth individuals pursuing litigation in return for taking a slice of their fortune once assets have been recovered.

The jewel in the crown for both sides is Akhmedov’s £230m yacht, Luna, which he bought from fellow oligarch Roman Abramovich. Boasting an onboard spa, two heliports and a mini-submarine, it has a missile detection system, bomb-resistant doors and an anti-drone device.

The vessel has been impounded by the authorities in Dubai while the warring parties continue to contest its ownership in the courts.

“Mr Akhmedov continues to fight all efforts of Tatiana and her backers, Burford Capital, to enforce what he has always said was a misguided and wrong judgment by the English high court on the opportunistic actions of his ex-wife and her legal team,” a spokesman for Akhmedov said.

A spokesman for Interpol said it rarely commented on specific cases or individuals.