Kavalenka's wife, Alena, told RFE/RL on July 27 that her husband had asked for a pardon after prison authorities increased pressure on him, including putting him in solitary confinement.
She said authorities suggested he could be released by July 3 if he asked for clemency.
She also said that despite the request, filed before the deadline, he has remained imprisoned.
Kavalenka, 37, was sentenced in February to 25 months in jail for violating the terms of his parole for a conviction on charges of "illegally displaying the banned Belarusian national flag."
Officials force-fed him before, during, and after the trial because of his hunger strike.
-- RFE/RL's Belarus Service