KIGALI, Rwanda — Diane Rwigara, Rwanda’s most prominent opposition figure, was cleared by the country’s high court on Thursday of all charges related to her election challenge against President Paul Kagame, after the judges found that the prosecution had failed to provide evidence of insurrection and forgery.

The courtroom, packed with diplomats and supporters, erupted in applause as the verdict was announced, and Ms. Rwigara and her mother, Adeline Rwigara, 59, who was acquitted of inciting insurrection and promoting sectarianism, were overcome with tears. Relatives who had prayed before the hearing for protection swarmed them with hugs.

The younger Ms. Rwigara, 37, who was arrested after trying to run for president last year, is a rare domestic critic of Mr. Kagame in a country that has shown little tolerance for political dissent.

The Rwandan leader has won praise for leading the country’s recovery from the 1994 genocide and for advances in economic development and women’s rights, but he has also come under fire from critics who accuse of him acting in an increasingly autocratic manner.