Movahedi, in her mid-20s, was charged with "encouraging corruption and debauchery" and sentenced by a court in Tehran to one year in prison on March 2, Derafshan added.
The lawyer said Movahedi had stated her opposition to the "compulsory hijab" and that she wanted to express her opinion in "a civil protest".
Movahedi has staged protests against the law in the past.
In December 2017, she stood on a pillar box on Enghelab Avenue without the mandatory long coat and raised her white veil on a stick, an act that was copied by women in different cities.
Enghelab means revolution in Farsi and the square and avenue are among the busiest areas in the capital.
Movahedi's move sparked similar protests by other women, including some at the same spot, and they soon won recognition as "Dokhtaran-e enghelab", or the Girls of Revolution Street.
Like other women who copied her, she was arrested, but she was only fined for her first protest.
In her latest case, she has already spent more than five months in prison even though she is eligible for a pardon and the judge promised he would look favourably on a request for parole, Derafshan said.
According to Derafshan the judge "had urged Movahedi to make a parole request and that he would grant it as soon as he received it," however bureaucratic hurdles have prevented Movahedi from sending in her request.
"Movahedi has repeatedly made the parole requests in writing, but none of them have been sent," by Gharchak Prison where she is incarcerated.
Movahedi is also now eligible to be part of a mass pardon, but because the prison authorities have not yet updated her legal status she cannot receive it, Derafshan said.
"We have tried many times to overcome this bureaucratic dilemma but more than a month later we are nowhere, that's why we've gone to the media," Derafshan said.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)