Havel made the call at the close of the Forum 2000 conference in Prague attended by Iranian Nobel Peace Prize winner Shirin Ebadi.
Havel, himself a former leading dissident, voiced support to Sotoudeh in the same way he previously supported dissidents in China, Cuba, Burma and other countries.
Sotudeh, who was arrested in early September, has defended a number of well-known intellectuals and political activists.
Rights groups including Human Rights Watch and Amnesty International have said that Sotoudeh was jailed “solely in connection with her work defending others."
You can read more about the increased pressure on Sotoudeh and Iranian lawyers involved in sensitive political cases here.