Independent lab tests on smuggled samples from late Russian opposition leader Alexey Navalny indicate he was poisoned while imprisoned in a Siberian penal colony, his widow Yulia Navalnaya has said.

Navalny, a vocal critic of Vladimir Putin, died in February 2024 at age 47, with Russian authorities claiming he collapsed during a walk.

Navalnaya has long accused Putin of responsibility and called on labs to release their findings, though the specific poison has not been disclosed, CNN has reported.

His death, following years of imprisonment after a previous Novichok poisoning, sparked international protests and renewed accusations of Kremlin involvement.