A Nigerian man has been sent to a mental institution in Kano state after he declared he did not believe in God, a humanist charity says.
Mubarak Bala, 29, is said to have been forcibly medicated by his Muslim relatives, despite being given a clean bill of health by a doctor, the BBC reported.
The International Humanist and Ethical Union (IHEU) said a Lagos-based group had asked a lawyer to take up his case.
Kano is a mainly Muslim state and adopted Sharia (Islamic law) in 2000.
The IHEU said when Mr Bala told relatives he did not believe in God, they asked a doctor if he was mentally ill.
Despite being told that he was not unwell, Mr Bala's family then went to a second doctor, who declared his atheism was a side-effect of suffering a personality change, the group said.
Mr Bala, a chemical engineering graduate, was forcibly committed to a mental institution but was able to contact activists using a smuggled phone.
IHEU spokesman Bob Churchill said the group was concerned about his "deteriorating condition" and called for his "swift release".