Canada announced new sanctions on Sunday against six Russian officials following the death of opposition leader Alexei Navalny last month in an Arctic prison colony.

The sanctions target “senior officials and high-ranking employees of Russia’s prosecution, judicial and correctional services,” a statement by Canada’s foreign affairs department said.

The six people “were involved in the violation of Mr Navalny’s human rights, his cruel punishment and ultimately, his death”, it said.

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“Alongside our partners, Canada will maintain pressure on the Russian government to conduct a full and transparent inquiry into the death of Mr Navalny,” Foreign Affairs Minister Melanie Joly said in a statement.

“This increased pressure on the Russian government sends a clear signal that human rights must be unequivocally respected.”

After the death of Navalny, Russian President Vladimir Putin’s most vocal critic, the Canadian government summoned Russia’s ambassador to “demand a full and transparent investigation” into his death.

Navalny died on February 16 in unclear circumstances in a penal colony in the Arctic, where he was serving a 19-year prison sentence for “extremism.” He was 47 years old.

His family and allies have accused the Kremlin of ordering him killed and Western leaders have said Putin is “responsible” for his death.