Russia's President Vladimir Putin has called for an end to "shameful" political killings in Russia, after the shooting of opposition politician Boris Nemtsov just outside the Kremlin walls, BBC News reports

He said the most serious attention should be paid to high-profile crimes.

The former Deputy Prime Minister, 55, was murdered last week and buried in Moscow on Tuesday, March 3.

The motive is unknown, but Putin's aides have rejected suggestions that he had any involvement.