When you run, or own, a country is personal wealth really important?
How much was Stalin worth? How do you put a value on the USSR?
The claims over the president's assets surfaced last month when the Russian political expert Stanislav Belkovsky gave an interview to the German newspaper Die Welt. They have since been repeated in the Washington Post and the Moscow Times, with speculation over the fortune appearing on the internet.
Citing sources inside the president's administration, Belkovsky claims that after eight years in power Putin has secretly accumulated more than $40bn (£20bn). The sum would make him Russia's - and Europe's - richest man.