This one ?
MOSCOW -- Russian scientist Roman Kovalyov, convicted and sentenced to a lengthy prison term in 2020 on a high-treason charge that he and his supporters rejected, has died of cancer.
The Pervy Otdel (First Unit) human rights group said on April 27 that Kovalyov, a former senior official at the Central Research Institute of Machine Building (TsNIIMash), was released from prison two weeks earlier to allow him to die at home.
Or this one?
Kudryavtsev was arrested in July 2018 on suspicion of passing classified data on hypersonic technology to a research group in Belgium. In April 2021, Kudryavtsev died of lung cancer at the age of 77.