Two Russian businessmen are set for a High Court showdown over a billion-pound business deal allegedly agreed in a London sauna.

The battle between Alexander Gorbachev and Andrey Guriev comes after a judge ruled Mr Guriev’s burly bodyguards attempted to block papers being served on the oligarch during a scuffle in a Mayfair street.

In a video shown to the court, Mr Guriev – a former Russian senator who owns London’s largest private house Witanhurst – can be seen with his entourage trying to load up two Bentleys.

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Guriev owns London’s biggest home after Buckingham Palace, according to the New Yorker. (BBC/PA)

Mr Gorbachev claims that his former business partner Mr Guriev swindled him out of a nearly 25% stake in Phosagro – a £4 billion London-listed firm chaired by former London Stock Exchange chief executive Xavier Rolet.

Mr Gorbachev alleges that during a series of meetings in 2005, including in a sauna and a pub in London, Mr Guriev said he was holding a 24.75% stake in the business in a trust for Mr Gorbachev, court documents show. Mr Guriev denies this. The stake would today be worth around £1 billion.

The two entered business together in Russia in the early 1990s, launching the predecessor to Phosagro in 1996.

They were close friends, with Mr Guriev even allegedly paying Mr Gorbachev’s way when the latter had to flee Russia on what he claims are trumped-up fraud charges. Meanwhile Mr Gorbechev helped run Phosagro while Mr Guriev spent 12 years as a senator in Russia.

The case against Mr Guriev can now be heard in a British court after a judge at the High Court in Manchester ruled the billionaire had been properly served the papers.

Dramatic footage from the scene played to the court shows a representative of Mr Gorbachev accosting Mr Guriev outside the Mayfair Hotel in central London.

The man approaches the group, who were seemingly returning from a shopping trip, brandishing court documents at them, but Mr Guriev’s entourage immediately get between him and the Russian.

“Sir, I’ve been instructed to hand you these papers. Er, they are very im…” he said. The papers are later dropped on the road. Afterwards Mr Guriev, dressed in a suit jacket and a green puffer coat, asked “What does he want?” in Russian.

The judge did not agree with Mr Guriev’s claims that his English was too poor to understand that the documents were for him.

“His knowledge of English would not stand in the way of realising that the remarks were addressed to him,” Judge Pearce said.

The judge stopped short of calling testimony from Mr Guriev’s henchmen deliberately false.

But he added: “Without having heard cross examination of these witnesses, I cannot safely conclude that all or any of them are lying, though I have a strong suspicion that this is so.”

The judge later denied Mr Guriev permission to appeal against the verdict.

A spokesman for Mr Guriev said: “This speculative judgment of the court is, in our view, unsound and will be appealed. The ruling simply deals with a procedural issue, nothing more, arising from a chaotic 30-second long incident in a busy street. It has no relevance to the substance of Mr Gorbachev’s claims, which we believe are entirely without merit.”

They added: “These claims are being pursued through sheer greed and will be defended forcefully.”

Mr Gorbachev claims to have co-founded Phosagro and helped build it into Europe’s largest phosphate fertiliser supplier with a market value of £4 billion.

The long-running battle between the two started when Phosagro listed in Moscow and London in 2011.