Social media site X, formerly Twitter, has restored the account of Yulia Navalnaya, the widow of Russian opposition leader Alexei Navalny, after it was mistakenly suspended.

The @yulia_navalnaya account page was accessible around 50 minutes after it was first suspended without explanation.

X then said that the "platform's defense mechanism against manipulation and spam mistakenly flagged" Navalnaya's account. "We unsuspended the account as soon as we became aware of the error, and will be updating the defense," it said.

The account was a new one created following the death of Navalny. Navalnaya last posted a video of Navalny's mother urging Putin to hand over her son's body.

Navalnaya blames Putin for killing her husband

Navalnaya has accused Russian President Vladimir Putin of "killing her husband"  and alleged that officials' refusal to hand over his body to his mother was a part of a cover-up.

She posted a nine-minute video to YouTube ahead of her meeting with European foreign ministers in Brussels on Monday, vowing to continue her late husband's work.

“We know exactly why Putin killed Alexei three days ago. We will tell you soon about it. We will also definitely find out who exactly and how exactly this crime was committed. We will name names and show faces,” she said in the video.

Russian authorities said Navalny died suddenly after collapsing following a walk in the remote "Polar Wolf" prison in the Arctic on Friday afternoon. The news was met with outrage around the world, with many world leaders placing the blame on Putin.

rm/nm (Reuters, AFP)