A lawyer for three European feminist activists who were imprisoned after a topless courthouse protest last month in Tunisia says their sentence has been commuted and they are to be freed immediately.

Souhaib Bahri said the women would leave Tunisia as soon as possible after Wednesday's decision suspending their sentences, cutting short their prison term of four months and a day.

The two French and a German member of the Ukrainian feminist group Femen maintained during the trial that there was nothing sexual or offensive about their protest and that it was to support their imprisoned Tunisian colleague.

The three women were convicted of public indecency, offending public morals and threatening public order after they demonstrated topless in front of the court building on May 29, a court official said.