The trial of Sviatlana Tsikhanouskaya's husband, whom she replaced as a candidate after he was prevented from running in last year's presidential election in Belarus, opened on Thursday.
Sergei Tsikhanousky, a popular video blogger, is one of six men standing trial. He, along with four others opposition figures, is accused of "preparation of mass disorder" and "incitement to hatred".
The trial is taking place behind closed doors at the Gomel detention centre, some 300 kms southeast of capital Minsk. Relatives have not been allowed to attend.
The Belarusian NGO Viasna broadcast a video of the arrival of the accused, their hands handcuffed behind their backs. They have been put in two different rooms and will attend the hearings in a cage.
Tsikhanousky, 42, was arrested on May 29, 2020, as he was campaigning for the August presidential election after becoming known for videos in which he denounced corruption and President Alexander Lukashenko.
According to his wife, who became the opposition's figurehead after his arrest, he now faces 15 years in jail.
"I don't know what to expect but definitely not justice," she wrote on Twitter.
Tsikhanouskaya fled to neighbouring Lithuania after being briefly detained following the election, in which Lukashenko was officially credited with over 80% of the vote. The ballot was ruled fraudulent by Britain, the European Union and the US.
She said the couple have only been allowed to speak once since his arrest and alleged that Lukashenko visited her husband in prison and offered him his freedom in exchange for loyalty.
"Sergei stood his ground and didn't betray his ideals. He supports me from prison," she went on. She also alleged ill-treatment with prisoners reportedly not given bed linen or warm clothing and repeatedly falling sick. "It should be considered torture."
The opening of the trial comes just two days after another former presidential candidate, Viktor Babaryko, who was considered Lukashenko's most serious rival when he was arrested, was sentenced to 15 years in prison.
Lukashenko's fraudulent election victory was met with mass demonstrations which he responded to with a vicious crackdown and the detention of thousands of people.
According to Viasna, more than 500 people are still jailed as political prisoners, including Roman Protasevich who was detained after Belarus forced his Ryanair flight from Athens to Vilnius to land in the country.