MOSCOW: A prominent Russian cartoonist won loud applause at a usually politics-free awards ceremony when he suggested President Vladimir Putin shared responsibility for the death of an anti-corruption campaigner in a Moscow jail.

Putin's opponents frequently lambast him during protests and on the Internet, but criticism of the president is rare at mainstream cultural events and in most broadcast media.

Cartoonist Yuri Norshteyn broke that taboo when he took the stage on Saturday and criticised Putin over the jailed lawyer's death in 2009 that prompted the U.S. Congress to impose sanctions on Russian officials.

Commenting on a previous speaker who had said Russia did not have enough doctors, Norshteyn said: "Immediately, I linked this ... with when Putin said Magnitsky died of heart failure."

"I think he died of a failure of heart on Putin's part and on the part of the prison boss," he said.

The comment was a reference to Putin's statement, at a news conference in December, that Magnitsky had "died not from torture, nobody tortured him, but from a heart attack." The Kremlin's own human rights council has said he was probably beaten to death.

After his initial comments, the rest of Norshteyn's speech at the awards ceremony was drowned out by applause and shouts of "Bravo!" in a clip that had received nearly 290,000 hits on YouTube by Monday afternoon.

Magnitsky, died after almost a year in jail on tax evasion and fraud charges that his colleagues said were fabricated by the investigators he had accused of stealing $230 million from the state through fraudulent tax refunds.

Nobody has been convicted of any crime in connection with the death of Magnitsky at age 37 who has become a symbol of the impunity which critics say Russian authorities enjoy and of the dangers faced by those who challenge them.

Washington adopted legislation last month known as the Magnitsky Act, which is meant to punish Russians it suspects of human rights violations by barring them from the United States and freezing any assets they have there.

Russia responded with a law that imposes similar sanctions on Americans it deems rights violators, outlaws U.S.-funded non-profit organisations considered to be involved in political activity and bars Americans from adopting Russian orphans.

The awards ceremony is scheduled to be broadcast on state-owned First Channel television later this week. The channel declined on Monday to say whether it would be aired in full.

Putin was greeted by boos and whistles when he stepped into the ring at a martial arts event in Moscow in November 2011, when he was prime minister, and opponents have mounted protests since then that have been the biggest of his 13-year rule.

The protests revealed deep dissatisfaction with Putin among many urbanites, but he won the presidency in March 2012 with nearly two-thirds of the vote.