Battle for London's largest private home: Billionaire Putin ally sues fellow Russian oligarch over fertiliser firm - with winner set to take £300m Highgate mansion that boasts underground 'village' and was backdrop to BBC's Fame Academy

A wealthy Russian exile is suing a sanctioned ally of Vladimir Putin in battle over a multi-billion pound chemical business - which could see him claim a £300m mansion second only to Buckingham Palace as the biggest house in London.

Alexander Gorbachev has taken Andrey Guryev to court in London over claims he is owed shares in the fertiliser firm PhosAgro.

Gorbachev, not a relation of former Soviet Union leader Mikhail, claimed he had a handshake agreement with billionaire Guryev that he would be given a share in the latter's business.

If his claim in the High Court in London is successful, Gorbachev could be given ownership of the £300m Witanhurst House - the largest private residence in London after Buckingham Palace.

The house itself is a luxurious retreat - with scores of rooms, an underground complex that reportedly boasts a cinema and a sauna, and a 70ft swimming pool.

Gorbachev has alleged Guryev offered only $30million (£23m) for his share of the business after he was forced out of Russia and given asylum in the UK; when he rejected this, Gorbachev was told he had no right to any share in PhosAgro.

The Grade II* listed home is one of Guryev's few known assets in the UK, and Mr Gorbachev's representatives expect him to try and claim the 25-bedroom Highgate estate if he wins, The Times reports.

The building will be recognisable to some as the grand estate once featured on the BBC's Fame Academy - a short-lived challenger to ITV's mighty Pop Idol.

Contestants stayed in the mansion's plush accommodation as they were whittled down - with songwriter David Sneddon and now-retired singer Alex Parks its only two winners.

Sneddon, who hails from Paisley near Glasgow in Scotland, has since carved out an enviable career writing songs for the likes of Lana Del Rey, Lewis Capaldi and Louis Tomlinson. 

The grand house itself reportedly boasts 65 rooms, including 25 bedrooms, 12 bathrooms and a walnut-panelled ballroom - some of which was seen on TV screen more than two decades ago.

Since then, the estate has been transformed with a host of new additions. 

It now boasts a subterranean complex of saunas, a cinema, a games room, a hair salon, staff quarters and even a car park with room for 25 vehicles. It connects to a 70ft swimming pool on the site. 

The estate also has 'The Orangery' - an additional, modern, Georgian-style house that was built on the site of a demolished wing around the same time.

It has living rooms, a kitchen and a media centre, with direct access to the underground village. Plans for the additions were signed off more than a decade ago after back-and-forths with Camden borough council.

Guryev, Russia’s 28th richest man with a fortune of £2.6billion, is also believed to own a penthouse in Vauxhall, which is close to the headquarters of MI6.

The feud between the pair and their subsequent High Court battle, which got underway yesterday, has been complicated by Guryev being sanctioned by the British government in relation to the war in Ukraine.

Guryev, who is an ally of autocratic Russian leader Vladimir Putin, will give evidence to Mr Justice Pelling KC in Dubai, with his own solicitors paying the trial judge's flights and accommodation fees.

Gorbachev claims he and Guryev ran mining firm Apatit in the late 1990s, with the business being owned by Menatep Group, a holding company of Mikhail Khordokovksy.

After the arrest of Khordokovsky in 2003 on tax evasion and fraud charges, Guryev convinced the Russian billionaire to sign over his shares in PhosAgro to him.

Khordokovsky would later be jailed, and fled to Britain following his release from prison in 2013, where he was granted asylum. 

Gorbachev, who was born in Moscow in 1962 and served as chairman of PhosAgro, fled to Britain from Khordokovsky's arrest.

He says he was forced to leave to avoid politically motivated fraud charges and was granted asylum in the UK in 2005.

He says that while in London he was offered $30million - the equivalent of around £23million - for his share in the business.

When he rejected the offer, he claims he was told he was not entitled to any share of PhosAgro, and has since taken the matter to court.

Both Guryev and Gorbachev have asked Mr Justice Pelling to act as a special examiner for the former at a meeting in Dubai.

During the meeting, which is taking place at the Dubai International Financial Centre, he will question Guryev about the case and take evidence from him.

Guryev came to public prominance last year after ex-Google CEO Eric Schmidt tried to buy his superyacht, the Alfa Nero.

The yacht, which has been abandoned in Antigua and Barbuda since March 2022, was due to be auctioned off by the Caribbean nation.

Schmidt won the auction with a bid of $67.6million (£52.5million), but withdrew after Guryev's daughter challenged the decision in court. 

The 267ft vessel can sleep 12 guests and contains a swimming pool that turns into a helipad.

While Guryev denied he owned the superyacht, his daughter, Yulia Gurieva-Motlokhov, later stepped forward to claim it.

After the government lifted sanctions on the vessel, officials in Antigua auctioned it off despite Gurieva-Motlokhov's attempts to block the sale.

Bloomberg reported that following this, her lawyers have been appealing to courts in Antigua to void the transaction.

According to the The US Treasury's Office of Foreign Assets Control (OFAC), Guryev is a known close associate of Russian President Vladimir Putin.

The OFAC said that he had previously served in the Russian Government from 2001 until 2013.