Yulia Navalnaya, widow of the late Russian opposition leader Alexei Navalny, has been detained by a Moscow court for alleged involvement in an 'extremist' group.

Despite living in exile, Navalnaya remains a prominent opposition figure, accusing President Putin of her husband's murder and calling for mass protests.

She has engaged with Western leaders, labeling Putin a 'murderer and war criminal,' and has been appointed president of a US-based human rights foundation.

The Kremlin denies involvement in Alexei Navalny's death, amidst a climate where dissenters face imprisonment or exile.

Navalnaya's arrest signifies the ongoing crackdown on opposition figures and critics of the Russian government.