A Rwandan court acquitted opposition figure Diane Rwigara on Thursday of all charges against her, including "inciting insurrection," in a case rights groups say was politically motivated.

The US-educated activist, 37, was facing a possible 22-year prison sentence for insurrection against the government and allegedly forging signatures of support so she could run for president.

She was barred from running against long-time leader Paul Kagame in 2017 elections and arrested shortly thereafter, along with her mother Adeline, who was also acquitted.

The judge at the court in the capital Kigali said there was not enough evidence against them.