UN human rights experts have called for the release of the Nigerian singer sentenced to death by hanging for blasphemy by an Islamic court in the northern state of Kano.

Yahaya Sharif-Aminu, 22, was sentenced on 10 August for sharing a song that he had written and performed via WhatsApp. The court ruled that the song had blasphemed Prophet Muhammad.

In a statement, 10 UN experts on human rights called for the sentence to be overturned, saying they were concerned that Sharif-Aminu – a Muslim who belonged to the Sufi Tijaniyyah order – was being held in communicado and did not have legal representation at his initial trial.

“Artistic expression of opinion and beliefs, through songs or other media – including those seen to offend religious sensibilities – is protected in accordance with international law. The criminalization of these expressions is unlawful. Music is not a crime,” the statement.