MOSCOW: Human Rights Watch on Thursday condemned the Russian authorities under President Vladimir Putin for unleashing the toughest crackdown against civil society since the fall of the Soviet Union in 1991.

"The Kremlin in 2012 unleashed the worst political crackdown in Russia's post-Soviet history," the New-York based rights watchdog said in an English-language statement released in Moscow accompanying the release of its annual world report.

"This (2012) has been the worst year for human rights in Russia in recent memory," the rights group quoted Hugh Williamson, its Europe and Central Asia director as saying.

"Russia's civil society is standing strong but with the space around it shrinking rapidly, it needs support now more than ever."

After returning to the Kremlin for a third term despite unprecedented protests against his 13-year rule, Putin signed off on a raft of laws in what critics saw as a bid to quash dissent.

The new legislation re-criminalised slander, raised fines for misdemeanours at opposition protests and forced non-governmental organisations that receive foreign funding to carry a "foreign agent" tag in a move seen as a throwback to Soviet times.