There have been claims of a ‘ring of death’ following the death of a London businessman in circumstances similar to four of his friends who had died in recent years.

Scot Young, 52, was killed after falling around 60ft from a fourth-floor window on to railings in upmarket Marylebone, London, on Monday.

It was described as a "grisly" and "brutal" scene.

Scotland Yard said his death was not being treated as suspicious.

But friends of Mr Young's have since come forward with concerns about a potential "ring of death" in his inner circle.

All five men - Mr Young, Johnny Elichaoff, Boris Berezovsky, Robert Curtis and Paul Castle - appear to have killed themselves after suffering financial setbacks over the past four years.

One anonymous source told the Daily Telegraph that the men were "bullied" to their deaths by the Russian mafia.

Last month, financial consultant and antiques dealer Johnny Elichaoff, 55, said to be a friend of Mr Young, died after plunging from a building in London.

Mr Elichaoff, the ex-husband of TV personality Trinny Woodall, fell from Whiteleys department store in Bayswater, west London, on 15 November.

Friends and family were said to be shocked that Mr Elichaoff, a former drummer who also appeared on TV, would take his own life.

Police said Mr Elichaoff’s death was not being treated as suspicious.

In March last year, Russian oligarch Boris Berezovsky, also a business associate of Mr Young, was found dead at his home in Berkshire.

The former billionaire and Kremlin critic was found with a ligature around his neck on the bathroom floor.

An inquest into his death ended with an open verdict. It heard Mr Berezovsky was in a depressed state when he died.

But his death raised suspicions, not least because of his closeness to the former FSB agent Alexander Litvinenko, who died after consuming radioactive Polonium in London in 2006.

Mr Berezovsky, who had lived in a self-imposed exile in the UK since 2000 after falling out with Vladimir Putin, survived a number of assassination attempts, including a bomb in his car which decapitated his chauffeur.

He made his fortune in Russia in the 1990s when he bought up state assets that were sold off cheaply.

His wealth was once valued at $3bn (£2bn), but he is thought to have suffered in the financial crisis. In 2009 his wealth was estimated at £450m.

In 2012, he lost a lawsuit against Chelsea owner Roman Abramovich which is thought to have cost him £100m.

Two other associates linked to Mr Young who died in the last four years were property tycoons Robert Curtis and Paul Castle.

Mr Curtis reportedly fell under a Tube train in northwest London in 2012.

Two years earlier, Mr Castle - who had played polo with Prince Charles - was also killed under a Tube train.

Mr Castle, Mr Curtis and Mr Young were all reportedly involved at one time in property deals with Russian billionaires.

However, all three had encountered financial problems before their deaths.

Mr Young was said to have had huge debts.

He had been embroiled in multimillion-pound battle for six years with his estranged wife Michelle, which saw him sent to prison.

In 2013, a judge ordered Mr Young to pay his wife £20m after ruling that he was worth £40m. Mrs Young had claimed that he was "worth billions" and said the settlement was "disgraceful".

Mr Young's American model girlfriend, Noelle Reno, said she was "distraught by the sudden loss of my best friend.”

She has not commented publicly about the suspicions surrounding his death.