Nigeria's state security service says it is still detaining journalist Omoyele Sowore - who is facing treason charges - despite him being granted bail, because nobody came to claim him.
But Sahara Reporters, the news website Mr Sowore founded, said his lawyers were denied access when trying to collect him from jail in Abuja.
Mr Sowore was detained in Lagos in August after calling for a revolution.
The arrest has sparked a public outcry against the intelligence service, DSS.
Mr Sowore was a presidential candidate in the general election last February.
An activist and journalist who usually lives in the US, he has been charged with treason, money laundering and "cyberstalking" for allegedly sharing false and insulting information about President Muhammadu Buhari, who won a second term in the elections.
He has called for a revolution because he said the election this year was not credible.
"All that is needed for a #Revolution is for the oppressed to choose a date they desire for liberty, not subjected to the approval of the oppressor," he tweeted on 2 August.
One day later, on 3 August, he sent another tweet: "DSS invades Sowore's".
This is the second time Mr Sowore has been granted bail but has subsequently not been released.
Is he free to leave jail on bail?
According to Nigeria's security services, known as the Department of State Services (DSS) - yes.
In a statement on Friday, the DSS said it had received a court order for the release of Mr Sowore, but nobody had come to claim him.
"It is important that the public notes that since the receipt of the Order, no person has turned up at the DSS to take delivery of him. This becomes imperative for reasons of accountability," it said.
But Sahara Reporters have disputed this, stating that Mr Sowore's lawyers were blocked when they attempted to collect him.
"On Saturday morning, lawyers and activists stormed the facility to take Sowore home but were met with stiff resistance by operatives, who said they had no clearance to let him go," it reported.
There has been widespread criticism of the DSS on social media over the case.
"This is a joke! Just open your damn gate DSS. He will go home or let me call UBER to pick him [up]!" wrote one Twitter user.