Russian President Vladimir Putin has urged that the "shameful" political killings should be put to an end, after the murder of opposition politician Boris Nemtsov.
According to BBC, Putin said that serious attention should be paid to high-profile crimes.
Nemtsov was murdered on Friday night outside Kremlin walls and buried in Moscow on Tuesday.
Putin's aides had rejected accusations that there was any involvement of the President.
At least 50,000 people had taken to the streets on Sunday to pay tribute to the murdered leader.