Kenya has deported opposition supporter and lawyer, Miguna Miguna following his role in the unofficial swearing-in of opposition leader Raila Odinga as "the people's president".
Mr Miguna has boarded a flight to take him to Canada, where he is a citizen.
The government says Mr Miguna has renounced his Kenyan nationality, which he denies.
TV stations were stopped to prevent them broadcasting the ceremony, which officials said was an act of treason.
Mr Odinga boycotted last year's election re-run, saying it would be rigged in favour of President Uhuru Kenyatta.
After Mr Odinga's unofficial swearing in on 30 January, Mr Miguna declared that he was "the one who signed the oath and conducted it" and goaded police to come and arrest him.
On 2 February, police broke down his door in a dawn raid and detained him.
Mr Miguna says he was then kept "in unlawful incommunicado detention for five days under the most horrendous, cruel and inhumane conditions imaginable".
On Tuesday, he appeared before a court outside Nairobi and was charged with "being present and consenting to the administration of an oath to commit a capital offence, namely treason".
The court had ordered that Mr Miguna be bailed following his hearing, but this did not happen.
Videos posted on social media then showed Mr Miguna on board a flight to Amsterdam, from where he was due to connect to Canada.
A spokesman for the ministry says that Mr Miguna renounced his Kenyan citizenship years ago, which he disputes.
"I have never, ever renounced my Kenyan citizenship and will never do that. I've never even contemplated it," Mr Miguna said in his statement.
"The constitution is crystal clear: no one can invalidate or purport to cancel the citizenship of a Kenyan born citizen," he added.
The government is now coming under pressure to explain under what law Mr Miguna was deported.
Under Article 17 of the Kenyan Constitution, a person born in Kenya can only have their citizenship revoked if it was acquired by fraud, if they or their parents were already a citizen of another country, or if the person was older than eight when they were found in Kenya.
Officials are expected to provide more detail about Mr Miguna's deportation later on Wednesday.
On Twitter, the government's newsroom simply said it was following court orders to release him.
Mr Miguna is the leader of the National Resistance Movement, a civil disobedience organisation linked to the opposition.
On 30 January, the government declared it an organised criminal group.
It wasn't Mr Miguna's first brush with the law.
In 1988, he was arrested by the then government of President Daniel arap Moi.
Mr Miguna then went to Canada where he claimed political asylum, according to his website.