A memoir written by Kremlin critic Alexei Navalny before his death in February under mysterious circumstances in a Siberian prison camp will be released in October, American publisher Alfred A. Knopf announced Thursday.

The memoir, titled "Patriot," is a testament not only to Navalny's life, but "to his unwavering commitment to fight against dictatorship —  a fight he gave everything for, including his life," said Yulia Navalnaya, Navalny's widow.   

She added the book would be released simultaneously in at least 11 different languages on October 22, including in Navalny's native Russian, although the book is unlikely to be available in Russia, as the political movement he led there has been outlawed. 

In a statement on Thursday, Navalnaya said through the memoir's pages, readers would get to know the man she loved deeply.

"Sharing his story will not only honor his memory but also inspire others to stand up for what is right and to never lose sight of the values that truly matter."

Kira Yarmysh, Navalny's spokesperson, wrote on the Telegram messanger service about how Navalny had begun to dictate parts of the book to her while he was convalescing in Germany only two months after his poisoning. 

Yarmysh added he had finished the book when in prison after returning to Russia in 2021.

"After the poisoning attempt in 2020, everyone insisted, 'Alexei, you should write a book.' He just shrugged it off. What kind of biography can be written at 44? It's barely halfway through life," widow Navalnaya said.

"He wasn't rushing ... there was still so much ahead. But things turned out differently. Horribly and very unfairly. It turned out there wasn't another half ahead," she added. 

The final words of Putin's fiercest critic 

Navalny was considered Russian leader Vladimir Putin's foremost critic, and was a charismatic opposition figure who tried to expose the corruption of Putin's regime to the Russian public. 

In 2020, he was poisoned with nerve agent, and was treated in Germany where he recovered. He returned to Russia in 2021 after the poisoning and was arrested immediately. 

Navalny was serving a 19-year prison sentence on extremism charges when he died, aged 47, while "taking a walk" in a Russian prison camp, authorities there said. His wife has blamed Putin for her husband's death, and has vowed to take up the mantle of Navalny's fight for a democratic Russia.

His death also led to worldwide grief as people around the world and in Russia —  where acts of political dissent carry big risks —  turned out to pay their tribute to Navalny. 

"It is the full story of his life: his youth, his call to activism, his marriage and family, and his commitment to the cause of Russian democracy and freedom in the face of a world super-power determined to silence him," Knopf said in a statement. 

rm/wmr (AFP, Reuters, AP)