Mr Kozlov was shot by two gunmen in Moscow late on Wednesday
Andrei Kozlov had spearheaded a drive to close Russian banks suspected of money laundering. The 41-year-old first deputy chairmen of Russia's central bank died on Thursday after being shot by two gunmen in Moscow.
The tributes that have been flowing reveal the high regard in which some political and business leaders held Mr Kozlov.
"A very courageous and honest personality, who has been on the frontline of the struggle against financial crimes," was how Finance Minister Alexei Kudrin described him.
"One of the most professional people in the entire Russian banking sector," said Anatoly Chubais, who runs Russia's electricity monopoly.
But others may not have felt that way.
Politicians believe Mr Kozlov's crusade against unreliable or criminal banks operating in Russia may have made him a potential target.
Mr Kozlov had been the central bank's first deputy chairman since 2002.
Mr Kozlov - who had spoken fluent English and German - started at what was the Soviet central bank at the age of 24.
Rising quickly through the ranks, he become first deputy chairman in 1997, at the age of 32.
The press noted his meteoric rise with praise.
"Andrei Kozlov is valued as a top-of-the-line professional. He is also given due credit as one of those who started the formation of the stock market in Russia," Kommersant Daily commented in October that year.
He left in 1999 for a spell in the private sector, but rejoined the central bank in April 2002.
There he became head of bank supervision, overseeing the withdrawal of licences from commercial banks accused of money laundering and other crimes.
In 2004, he intervened in Sodbiznesbank, a small Russian bank that was accused of laundering ransom money from hostage-taking.
This resulted in central bank officials seizing control of the bank which sent shock waves through the banking sector.
Only last Friday, Mr Kozlov told a banking conference in Sochi the central bank sought the lifetime disqualification of bankers found responsible for tax crimes and money laundering.
"Those who have been found out laundering criminal money should probably be barred from staying in the banking profession for life. Such people disgrace the banking system," he was quoted as saying by Russia's Interfax news agency.
The Russian press says Mr Kozlov stood out as unusually open in the closed world of Russian banking, becoming a public face for attempts to clean up the industry.
But he had frequently been the target of smear campaigns in Russian newspapers and on websites.
One of Mr Kozlov's achievements had been the introduction of a deposit insurance scheme designed to restore faith in the banking system after the 1998 banking crisis, in which many Russians lost their savings.
In addition to the banks whose licences were revoked at Mr Kozlov's initiative, he had effectively earmarked many others for closure by refusing them access to the deposit insurance scheme.
The speaker of the State Duma, the lower chamber of Russia's parliament, told reporters he believed Mr Kozlov was killed in a "contract hit".
"The central bank revoked licenses of a number of banks, and it's quite possible that the gangsters linked to them might have put out a contract on him," Boris Gryzlov said.
Mr Kozlov is survived by his wife and three children.
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