"The killer of Ali Karim, son of the activist Fatima al-Bahadly, has been arrested" in the northern region of Kurdistan, the interior ministry said.

The autonomous region's security services said the man from Basra had "confessed to the crime", and was handed over to the federal authorities.

Karim, 26, had disappeared in Basra on Friday before his body was found the next day with gunshot wounds to the head and chest.

His mother, Bahadly, founded an organisation that works to protect and educate women and campaign against the recruitment of youths by armed groups.

Activists say she often receives threats.

The murder of her son "appears to be yet another in a growing list of attacks and killings" targeting Iraqi human rights defenders and their families, the Dublin-based rights group Frontline Defenders tweeted Monday.

The European Union's ambassador to Iraq, Martin Huth, has called for a prompt investigation into the killing.

Dozens of activists have been killed or abducted, sometimes briefly, since a popular uprising in late 2019 demanding political change and a curb to Iran-backed factions in Iraq.