Australia has imposed financial sanctions and travel bans on seven Russian prison officials after the nation’s opposition leader Alexei Navalny died in custody.

Until his death on February 16, Navalny had been held at the “Polar Wolf” Arctic penal colony, which the government says was known for its systematic abuse of prisoners.

These latest sanctions are part of the federal government’s attempts to hold to account those responsible for the death of Russian President Vladimir Putin’s most formidable domestic opponent.

“He was regularly mistreated, denied healthcare and placed in prolonged periods of solitary confinement,” a government statement said.

“We acknowledge Mr Navalny’s heroic contribution to promoting democracy in Russia and his tireless opposition to President Vladimir Putin’s regime – work for which he has paid the ultimate price.”

A former lawyer, Navalny rose to prominence more than a decade ago through his documentation of what he claimed was widespread corruption among elite Russian society.

He received international recognition when he announced his entry into the Russian presidential race in 2016, putting himself in direct opposition to Putin.

Navalny was repeatedly jailed and in 2020 claimed he was poisoned by the Kremlin, though Russia has denied this.

After receiving treatment in Germany, Navalny returned to Russia in 2021 and was promptly arrested before being sentenced and sent to the maximum security penal colony to serve a three-decade term.

According to the prison service, the opposition leader “felt unwell” after a walk at the IK-3 penal colony and lost consciousness.

Attempts to revive him “did not yield positive results”, they said in a statement.

Assistant Foreign Affairs Minister Tim Watts pointed the blame at the Russian government, as the Commonwealth more broadly called for an independent investigation into the 47-year-old’s demise.

“Australia holds the Russian Government solely responsible for Alexei Navalny’s mistreatment and death in prison,” Watts said in a tweet on Monday.

Australia’s Magnitsky-style sanctions allow the government to target serious violations of human rights

First used in March 2022 to target the Russians responsible for the death of Sergei Magnitsky, who was killed after exposing corruption, they have since been applied to those involved in Mr Navalny’s poisoning and a similar attempt on the life of democracy activist Vladimir Kara-Murza.

– AAP