The European Court of Human Rights imposed a fine on Moscow for its inadequate investigation of Boris Nemtsov's murder.
The European Court of Human Rights (ECHR) condemned Russia on Tuesday for failing to carry out an adequate investigation following the assassination of Boris Nemtsov, one of Vladimir Putin's main opponents.
The case had been referred to the ECHR by Zhanna Borisovna Nemtsova, the daughter of the former opposition leader.
Nemtsov was shot four times at close range on a bridge, a stone's throw from the Kremlin on 27 February 2015.
"The Court found in particular that the Russian authorities had not adequately investigated the identity of the persons who had organised and ordered the assassination," the ECHR said.
The Russian investigation failed to probe the motive behind the assassination following allegations that state officials were involved, it added.
"Overall, the investigation was characterised by a lack of effectiveness," the Strasbourg-based court said.
The ECHR ordered Moscow to pay Boris Nemtsov's daughter €20,000 for "non-pecuniary" damage.
Russia had also violated Article 2 of the European Convention on Human Rights, which guarantees the "right to life," according to the court.
Boris Nemtsov played a prominent role as Vladimir Putin's opposition and had been deputy prime minister under President Boris Yeltsin.
In July 2017, five men from the republics of Chechnya and Ingushetia in the Russian Caucasus were sentenced to between 11 and 20 years in prison for the murder.
However, Boris Nemtsov's family denounced the investigation as a "total fiasco," blaming the Russian justice system for failing to identify the real culprit.