ROME, Italy - Italy's deputy prime minister Matteo Salvini, once an outspoken admirer of Russian President Vladimir Putin, landed himself in hot water Tuesday with a comment on the death of the Russian opposition leader Alexei Navalny.

The head of the anti-immigrant League party, said it was "up to Russian doctors and judges" to determine the cause of Navalny's death.

Putin's main political opponent died in a remote Arctic prison on Friday, according to Russian authorities.

Navalny's team says the 47-year-old was murdered and western countries have blamed Russian authorities for the death.

Asked about Salvini's remark, EU foreign policy chief Josep Borrell said EU member states had adopted a joint declaration attributing responsibility for Navalny's death "to President Putin and the Russian authorities".

"It is a declaration approved by Italy," he said, adding that he advised "members of governments to simply read what their governments approve and adopt."

Opposition politicians were quick to seize on Salvini's comment.

"The judgment of the magistrates in a dictatorship has no value," the head of the centrist Azione party, Carlo Calenda, wrote on X, the former Twitter.

The League signed a co-operation deal with Putin's ruling party in 2017, deepening their ties.

Calenda threatened to file a no-confidence motion against Salvini if he did not produce a document proving he has since severed ties with Putin.