US intelligence agencies believe that while the Russian president bears full responsibility for the death of opposition leader Alexei Navalny, he did not order it to happen when it happened, the Wall Street Journal reported Saturday.

The discovery, which the magazine said was based on both classified intelligence and an analysis of publicly available facts, raises new questions about Navalny's death in a remote Arctic prison camp, which led to a new round of sanctions against President Vladimir Putin's Russia.

Among these facts was the timing of the opposition leader's death in mid-February, which overshadowed Putin's re-election a month later.

While the new finding does not cast doubt on Putin's responsibility for Navalny's death, the CIA and other U.S. intelligence agencies believe he likely did not give the order "at that moment," the magazine said, citing people familiar with the matter.

It said some European officials briefed on the US findings were skeptical that the 47-year-old dissident could have been targeted without Putin's prior knowledge, given the tight controls in Russia today.

President Joe Biden and several other world leaders have publicly expressed little doubt about the matter. “Make no mistake. “Putin is responsible for Navalny’s death,” Biden said after the stunning news of the death broke.

The Russian prison service said Navalny lost consciousness on February 16 after a walk in an isolated camp. It said attempts to resuscitate him were unsuccessful.

In a video taken a day earlier, Navalny appeared relatively healthy and in good spirits.

The week before, he was reportedly the subject of high-level talks over a possible prisoner exchange that could free him.

Navalny was serving a 19-year prison sentence on charges that he and his supporters said were fabricated.

He previously survived a poisoning that the US and other investigators blamed on the Kremlin. Russian officials have denied any responsibility for the poisoning or death.

In recent years, a number of prominent Kremlin opponents have died, been jailed or forced into exile.

The National Security Council declined to comment on the report when contacted by AFP.