Rwandan police on Monday arrested Diane Shima Rwigara, a leading critic of President Paul Kagame, charging her with forgery and tax evasion.
Her mother and sister were also arrested on the tax charges.
Earlier this year, electoral authorities barred Rwigara from standing in Augustโs presidential vote, which Kagame won, saying she had not submitted enough supportersโ signatures and some of the names she did sent in belonged to dead people.
Rwigara denied the allegations.
โThey are accused of tax evasion and secondly Diane Rwigara is accused of using fake documents while she was gathering signatures for (her) presidential candidacy,โ police spokesman Theos Badege told reporters on Monday.
Police said they had a warrant issued by a prosecutor to arrest them.
Rwigara, a 35-year-old accountant, has repeatedly accused Kagame of stifling dissent and criticised his Rwandan Patriotic Frontโs near total hold on power. Kagame won last monthโs election with 98.8 percent of the vote..
Kagame won international praise for presiding over a peaceful and rapid economic recovery in Rwanda since the 1994 genocide, when an estimated 800,000 people Tutsis and moderate Hutus were killed.
But he has also faced increased criticism for what human rights groups say are widespread abuses, a muzzling of independent media, and suppression of political opposition.
Rwigara claimed that she was being held under house arrest before Mondayโs police action.
โTell us why we are being arrested? Why should we go to the police while you have confined us to this place and took away all our money without leaving us any?โ Rwigara said as she and her family were being taken away.
Asked about this, Badege, the police spokesman, said that earlier police had only searched Rwigaraโs home and taken a few items and money away in line with the law.
It was a clear application of the law,โ Badege said.