A Russian banker shot five times close to London's financial district had been days away from giving evidence to an investigation into the attempted murder of a former business associate, his lawyer has said.
German Gorbuntsov, who at the height of his business empire owned four Russian banks, was walking towards his apartment block near the Canary Wharf banking district when a gunman opened fire on Tuesday evening, leaving him badly injured.
London police said on Saturday they were keeping an open mind about the motive of the attack.
Gorbuntsov's lawyer, Vadim Vedenin, said the 45-year-old remained in a medically induced coma to give him a chance to recover, and that doctors were hoping to revive him in about three days.
Vedenin said his client had been due to give evidence before the end of the month to an investigation by Russian prosecutors into the attempted murder of another Russian banker and former business associate of Gorbuntsov's, Alexander Antonov, in 2009.
"He was preparing to give evidence on certain people. He has already given it in written form and he was going to do so in official testimony," Vedenin said by phone on Saturday, adding that Gorbuntsov had come to London because he feared for his life.
The attack occurred outside the door of a block of high-end serviced apartments a short walk from the skyscrapers of Canary Wharf.
A member of the building's staff, who declined to give his name, said he heard no shots, but ran outside when he heard frantic shouting.
"He is a customer here. He was still alive. He spoke to us in Russian. I understood what he was saying," the member of staff, a Polish man, said. "He was swearing a lot."
London is home to thousands of Russian business people seeking capital, prestige and, in many cases, a haven from the rough and tumble of their home country's financial world.
Alexander Antonov made his career in the nuclear industry, then became its banker as owner of Konversbank, a financial institution founded to serve the nuclear industry about two decades ago.
Antonov said he and Gorbuntsov had disagreed over the terms of a bank sale just before the debt crisis of 2008, but that there had been no acrimony.
"Our relationship is friendly, and it has always been friendly," he told Reuters. "I have a great personal interest in his testimony."
The attempt on his life in 2009 was linked in Russia to the 2008 murder in Moscow of Ruslan Yamadayev, a powerful opponent of the Kremlin-backed Chechen leader Ramzan Kadyrov.
The two incidents were tried as a single case and three men were convicted. But the person or persons who ordered the murders was never identified, and the case had lain dormant until this year.
Diplomatic relations between Russia and Britain have been tested by a series of disputes involving Russian emigres.
Russia has refused to extradite the man suspected of murdering former Russian spy Alexander Litvinenko by putting radioactive polonium in his tea in London.
Meanwhile London courts have refused to extradite men wanted in Russia, including the Russian tycoon Boris Berezovsky, a former Kremlin insider turned fierce critic with criminal convictions in Russia.
Berezovsky, who says the charges brought against him in Russia are politically motivated, said by telephone from London that he did not know Gorbuntsov personally, nor did he know of any Russian criminals hiding out in London.
"One can give differing views, but it is important to understand that, from my not-exactly-dilettantish point of view, there is no place safer than London from Kremlin bandits or from Russian or international criminals," he said.
"But that of course is no guarantee they won't get you."