Alexei Navalny's spokeswoman, Kira Yarmysh, confirmed Navalny's death on Saturday, citing an official notice given to Navalny's mother, Lyudmila, who traveled to the prison in northern Russia.

Yarmysh, writing on X, formerly known as Twitter, demanded that Navalny's body be immediately released to his family.

She said Navalny died at 2:17 p.m. local time (0917 GMT) on February 16, according to a notice given to his mother.

Russia's prison service said 47-year-old Navalny fell unconscious and died on Friday, after taking a walk in the Arctic penal colony.

Where is Navalny's body?

However, Navalny's relatives have not yet seen his body.

According to Yarmysh, the politician's body was not in the morgue in Salekhard, the town near the prison colony where Navalny died.

"Alexei's body is not in the morgue," Yarmysh said on X.

Yarmysh said Navalny's mother and lawyer had visited the morgue to find it closed, despite assurances from the prison colony that it was working and Navalny's body was there.

Later, Yarmysh wrote on X that Russian authorities directly said that Alexey's body would not be handed over to his relatives until the investigation was completed.

According to prominent Navalny ally Ivan Zhdanov, Navalny's mother and lawyer were told at the prison colony that the politician had died of "sudden death syndrome."

Over 200 mourners arrested across Russia

People in Russia mourned the opposition leader despite the threat of arrest. According to rights group OVD-Info, at least 212 people have been detained across the country following Navalny's death.

109 people were detained in St. Petersburg alone, the online outlet ovd.info reported Saturday morning. Arrests were made in 21 cities, including Moscow, Bryansk and Krasnodar, it said.

In Moscow and other cities, men in civilian clothes or city cleaners spontaneously cleared away memorials erected for Navalny. 

But despite the removal of the memorials, people continued to lay fresh flowers, light candles and put up pictures in memory of the opposition leader, according to media reports.

UK will take action over Navalny's death

There will be "consequences" for the death of Alexei Navalny, British Foreign Secretary David Cameron said, as Western capitals pinned the blame on Russian President Vladimir Putin.

In London, the Foreign Office summoned Russian diplomats and demanded a "full and transparent investigation" into Navalny's death.

Meanwhile, G7 foreign ministers meeting in Munich held a minute's silence for Russian opposition leader Alexei Navalny, Italian Foreign Minister Antonio Tajani's office said.

Tajani "opened the G7 ministers' meeting in Munich by asking for a minute's silence in honor of Alexei Navalny," the ministry in Rome, which is leading the Group of Seven this year, said.

"For his ideas and his fight for freedom and against corruption in Russia, Navalny was in fact led to his death," the ministry quoted Tajani as saying.

dh/rc (dpa, Reuters)