An Indonesian woman has been flogged 100 times in Aceh province for adultery while the male involved, who denied the accusations, received just 15 lashes.

Ivan Najjar Alavi, the head of the general investigation division at the East Aceh prosecutors’ office, said the court handed down a harsher sentence for the woman after she confessed to investigators she had sex outside of her marriage.

Judges found it difficult to convict the man, who was then the head of the East Aceh fishery agency and also married, because he denied all wrongdoing, Alavi said.

“During the trial, he admitted nothing, denying all accusations. Thus, [judges] are not able to prove whether he is guilty,” Alavi told reporters after a public flogging for sharia law offenders in Aceh on Thursday.

Aceh is the only region in Muslim-majority Indonesia to impose sharia law, which allows whipping for charges including gambling, adultery, drinking alcohol and gay sex.

As an alternative ruling, the judges found the married man guilty of “showing affection to a female partner who is not his wife” after the couple were caught at a palm oil plantation in 2018.

He was initially sentenced to 30 lashes but his successful appeal at the sharia supreme court in Aceh reduced the sentence to 15.

The woman’s flogging was briefly paused because she could not bear the pain, according to an Agence France-Presse reporter in the field.

A man convicted of having sex with a minor was also whipped 100 times. He would serve 75 months in prison after the flogging, prosecutors said.

Dozens watched, recorded and uploaded to social media footage of the floggings, a public spectacle criticised by rights groups but which regularly attracted hundreds of onlookers before the pandemic.

Unlike the rest of the nation, Aceh follows religious law as part of a 2005 autonomy deal agreed with the central government that ended a decades-long separatist insurgency.

Human rights groups condemn public caning as cruel, and Indonesia’s president, Joko Widodo, has called for it to end. However, it has strong support among Aceh’s population.