German Gorbuntsov was in the foyer of his apartment block near Canary Wharf when a would-be assassin sprayed shots at him with a submachine gun.
The 45-year-old collapsed at the scene and was fighting for his life last night. Armed police are on guard at the hospital where he is in a coma.
Coma: German Gorbuntsov was repeatedly shot outside a block of flats near Canary Wharf in an attempted assassination attempt
Gun blast: German Gorbuntsov is pictured here being carried into ambulance after being shot in Canary Wharf
Friends of Mr Gorbuntsov fear that a mafia contract has been taken out on his life because he was a witness in the case of an attempted murder of another banker in 2009.
His neighbours in Byng Street on the Isle of Dogs, where serviced apartments cost up to £200 a day, said a tearful blonde tried to reach the banker’s prone body.
Emma Key, 30, said the woman – in her 20s and thought to be his wife – was being held back by police officers.
‘She was obviously upset, she was crying. She was trying to get into the ambulance. A policeman was trying to hold her back.
‘The concierge told us he had been shot three times and that that was his wife.’
Tony Smith, a 26-year-old estate agent, drove down Byng Street only moments after the murder attempt.
Murdered: Alexander Litvinenko, 43, died after being poisoned with radioactive polonium-210 in November 2006
He said: ‘I pulled my car up and looked down and saw his body, saw him.
‘Police were surrounding him but there were only two police cars, and the rest came later.
‘The window was shot out on the door. I thought he had been stabbed at first. I didn’t expect this to happen in this block.’
Mr Gorbuntsov has been linked to an investigation into a gun attack on Alexander Antonov, whose son Vladimir once owned Portsmouth Football Club.
New evidence from Mr Gorbuntsov led to the case being reopened by the judicial authorities in Moscow.
The case had been put on ice because the mastermind behind the attack remained unidentified even after three Chechens had been convicted of trying to kill Mr Antonov.
The same gang was also found guilty of assassinating Ruslan Yamadayev, one of five brothers from a clan that had challenged the power of Chechnya’s Kremlin-backed president, Ramzan Kadyrov.
Vadim Vedenin, Mr Gorbuntsov’s lawyer, told Kommersant newspaper in Moscow that his client’s new testimony in the Antonov case had implicated two of his former business partners.
The Russian banker had himself been suspected of involvement at one point.
The inquiry into Tuesday evening’s shooting is being led by the Metropolitan Police Trident gang crime command, which is said to be liaising with counter-terrorism officers.
Yesterday a spokesman for Scotland Yard said it was too early to speculate on whether the attack was linked to the Antonov investigation of 2009.
He also refused to reveal what weapon was used.
The attempted assassination will prompt comparisons with the murder of Russian dissident Alexander Litvinenko in London in November 2006.
British prosecutors have named his fellow ex-KGB agent Andrei Lugovoy as the main suspect in his poisoning with radioactive polonium-210.
Shooting: German Gorbuntsov, 45, was attacked on the Isle of Dogs close to Canary Wharf
However, the Russian authorities have repeatedly refused to send him to face trial in the UK.
Last night Mr Litvinenko’s widow, Marina, sent her thoughts to Mr Gorbuntsov’s family.
She said: ‘This must obviously be a very difficult time. I don’t think it is very easy to say what has happened at this stage – they will be hoping for some clarity very soon.’
Mr Gorbuntsov, who used to own a number of banks in Russia and Moldova, has been living in exile in Britain.
He is on Moldova’s wanted list over allegations of involvement in an illegal bank takeover and embezzlement. Another of his lawyers, Valery Andronik, told Kommersant that the attack was unlikely to have been planned from within the former Soviet republic.
‘He told me several times, “If I go back to Russia, they will kill me”,’ said Mr Andronik.
It is understood that Mr Gorbuntsov spent time in jail before becoming a businessman in the early 1990s.
He set up nearly 40 companies involved in security, construction, real estate and finance.
Although counter-terror officers are involved, Mr Gorbuntsov’s shooting is being put down to organised crime.
A Scotland Yard spokesman said: ‘A man was shot a number of times as he entered a block of flats by a suspect who is described as white, six feet tall and of slim build.
‘He was wearing dark clothing and seen running away.’