Amnesty International has been accused of "siding with tyrants" and bowing to Moscow's misinformation campaign after it stripped Russian opposition leader Alexei Navalny of his "prisoner of conscience" status, BBC and Reuters reported on Thursday.

The nongovernmental organization said Navalny did not deserve the designation because he advocated hatred in the past. Navalny was sent to prison last week after surviving an assassination attempt apparently carried out by Russian security services.

The international human rights group said it nonetheless was still calling for Navalny's release, adding he was being persecuted on fabricated charges for his vocal opposition of Russian President Vladimir Putin.

"Some of these comments, which Navalny has not publicly denounced, reach the threshold of advocacy of hatred, and this is at odds with Amnesty's definition of a prisoner of conscience," Reuters quoted Amnesty International as saying in a statement.

Navalny was designated by Amnesty as a prisoner of conscience last month after his arrest upon his return to Russia from Germany, where he received medical treatment following a life-threatening exposure to a Soviet-era chemical agent known as Novichok.

A representative for Amnesty in Moscow told BBC that he believed the series of calls to "de-list" Navalny was part of an orchestrated effort to "discredit" Putin's most vocal critic and hinder the rights group's requests for his release from detention.

Navalny was sentenced to three and a half years imprisonment this month after being found guilty of violating the parole conditions of a 2014 suspended sentence. His imprisonment sparked massive protests across Russia and a global outage, including the support of Amnesty International.

"If Amnesty International will only call out the persecution of saints, they are siding with tyrants," Tom Tugendhat, chairman of Britain's Foreign Affairs Select Committee, said in remarks quoted by The Telegraph.

"The prisons will be full and they'll stay silent as ordinary, flawed human beings are persecuted for crimes of conscience," Tugendhat said.