Cambodia's exiled opposition figurehead Sam Rainsy was sentenced in absentia to 25 years in jail Monday over an alleged plot to overthrow strongman Hun Sen's government, a court official said.
Rainsy has lived in France since 2015 to avoid jail for several other convictions he says are politically motivated.
The latest sentence was related to his attempts to return home in 2019, the government-friendly media outlet Fresh News reported.
Rainsy was convicted "for an (attempted) attack in Cambodia in 2019", Y Rin, a spokesman for Phnom Penh Municipal Court, told AFP, refusing to give further details.
The court also stripped Rainsy of the right to vote and stand as a candidate in an election, the official said.
In a statement on Twitter, Rainsy said the conviction was "born out of weakness and fear".
"Cambodian Prime Minister Hun Sen is afraid of any risk of my returning to the Cambodian political scene," he wrote.
"Hun Sen also dreads the prospect of any free and fair election which would inevitably lead to the end of his autocratic regime."
Eight other opposition politicians, including Rainsy's wife, were also sentenced in absentia to between 20 and 22 years in jail.
Hun Sen is one of the world's longest-serving leaders, maintaining a 36-year grip on power with methods that critics say include jailing political opponents and activists.
He has said he regarded Rainsy's planned return as a "coup attempt".
Since the election in July 2018, when Hun Sen's party won every parliamentary seat in a vote without a credible opposition, the Cambodian authorities have stepped up arrests of former members of the dissolved opposition party, human rights defenders and dissenting voices.
Around 150 opposition figures and activists have been put on a mass trial for treason and incitement charges, mostly for sharing messages on social media platforms supporting Rainsy's attempt to enter the kingdom.
Rights groups have slammed the trial as a politically motivated sham.
While many opposition politicians have fled Cambodia fearing arrest, the country's main opposition leader Kem Sokha is facing a separate treason trial, which has been indefinitely delayed since March last year.
Cambodian Opposition Figure Slapped with 25-year Jail Sentence