Police are currently searching for Alexei Moskalev, a 53-year-old single father sentenced to a two-year jail term after his daughter drew pictures at school exhibiting anti-war sentiments.
Moskalev had been under house arrest pending trial, but did not appear Yefremov to hear the verdict.
The court press secretary said that he had escaped house arrest and that his whereabouts were currently unknown.
Moskalev has been separated from his 13-year-old daughter, Masha, since he was placed under house arrest at the beginning of the month.
Masha, who is estranged from her mother, was moved to a state-run children’s shelter following the arrest.
The family has faced increasing pressure since last April when Masha Moskaleva’s school alerted police to drawings she had made apparently in protest of the war and in support of the Ukrainian people.
The drawing featured a mother and daughter holding hands as missiles fly toward them.
To the left of them is a Ukrainian flag reading “Glory to Ukraine” and to the right is a Russian flag that says, “No to war!”
In response, school officials summoned police, who questioned Masha about the drawing and threatened her father.
Moskalev was investigated and charged with discrediting the armed forces after police found social media posts in which he called the Russian regime “terrorists” and described the Russian army as “rapists.”
His lawyer, Vladimir Biliyenko, said that Moskalev was worried that his daughter was not with him while he was held under house arrest.
Prior to the court verdict, Mr Biliyenko visited the children’s shelter where Masha was held, and later told local reporters that she had written a letter to her father, saying “Dad, you are my hero.”
Mr Biliyenko also expressed surprise at Moskalev’s disappearance, though he is one of many Russian citizens, politicians and activists to have fled the country while pending trial.
“I’ve never seen anything like it,” said Mr Biliyenko.
“No client of mine has ever gone missing like this. I don’t know when he fled, or if he has.”