Bahrain's opposition leader, Sheikh Ali Salman, has been handed a life sentence after the Court of Appeal found him guilty of spying for Qatar.
The ruling comes just months after the Bahraini High Court of First Tier acquitted Salman of the charge of "colluding" with the rival state.
Bahrain cut ties with Qatar in 2017.
Human rights group Amnesty has described the decision as a "travesty of justice" amid Bahrain's "continued crackdown on dissent".
"This verdict... demonstrates the Bahraini authorities' relentless and unlawful efforts to silence any form of dissent," Amnesty's Middle East and North Africa director Heba Morayef said.
"Sheikh Ali Salman is a prisoner of conscience who is being held solely for peacefully exercising his right to freedom of expression."
Ali Salman, who led the now outlawed Al-Wefaq movement, was accused of plotting with Qatar to stoke anti-government unrest in 2011, along with fellow opposition leaders Hassan Sultan and Ali al-Aswad.
They have also received life sentences, reports BBC.