Yulia Navalnaya, the wife of Kremlin critic Alexei Navalny, who died mysteriously in prison, posted for the first time on Sunday after her husband's death.

Taking to Instagram, Navalnaya posted a picture of herself enjoying a moment with Navalny, two days after his death.

The caption of the poignant post read, "I Love You."

Kira Yarmysh, the spokesperson for the late Russian opposition leader, confirmed Navalny's death and demanded that his body be handed over to his family "immediately." Yarmysh also accused Russian officials of lying to delay the process, CNN reported.

Yarmysh's statement comes after the Russian prison service said that Russian President Vladimir Putin's critic, Navalny, died on Friday after he felt 'unwell' during a walk in his prison and fell unconscious.

The cause of his death is not clear.

Navalny had returned to Russia in 2021 from Germany, where he was undergoing treatment after being poisoned with Novichok.

Upon arrival, Navalny was arrested on charges he dismissed as politically motivated.

Reports of Navalny's death sparked outrage, with some Western leaders blaming Putin.

United States President Joe Biden said that he is "outraged" by Navalny's death and blamed Russian President Vladimir Putin.

British PM Rishi Sunak, French President Emmanuel Macron and European Union President Ursula von der Leyen also condoled Navalny's demise while pinning the blame on Moscow.