Andrei Kozlov, who was the first deputy chairman of Russia's central bank, was apparently ambushed by gunmen as he left a football ground following a match in what is believed to be a contract killing.
Government officials say they suspect that Mr Kozlov's death was linked to his campaign of shutting down financial institutions suspected of engaging in illegal activity.
Around 44 Russian banks have already lost their licenses due to money-laundering, thanks to tougher laws imposed by Mr Kozlov, winning him many new enemies.
Paying tribute to the deceased, finance minister Alexei Kudrin said: "He was at the cutting edge of the battle against financial crime.
"He was a very brave and honest man and through his activity he repeatedly encroached on the interests of unprincipled financiers."
An investigation into the murder has now been launched.