A former member of the Ugandan rebel group Lord's Resistance Army (LRA) has testified before the International Criminal Court (ICC) on Thursday (26 January 2017) during the trial of one of the LRA's most feared commanders, Dominic Ongwen, who faces 70 charges of war crimes and crimes against humanity.

Led by the Ugandan warlord Joseph Kony, the rebel group has committed human-rights violations against civilians for nearly three decades, abducted tens of thousands of children for use as soldiers and sexual slaves, and killed and maimed people across Uganda, the Congo, South Sudan, and the Central African Republic (CAR).

Ongwen's trial started on 6 December 2016, but the first prosecution witness only appeared before the court in the past 10 days.

A former LRA radio operator, who was identified only as P-016 and whose face appeared pixelated as he was filmed, was questioned by defence lawyers on Wednesday (25 January).

Defence lawyers are arguing that Ogwen, who was himself a child soldier, acted under the terror and authority exercised by Kony on LRA fighters.

Ogwen, lawyers say, was a victim caught in a system of which he did not have any means of control. According to his family, Ongwen was abducted by LRA fighters on his way to school in 1990, at age 10.

"What I know is that when Joseph Kony gives you an order and you do not apply it, you're arrested, detained, punished, you're beaten," the radio operator, who fled the rebel group 12 years ago, said.

"If I remember correctly when Dominic Ongwen separated from the main group, Kony was not happy, he sent men to fetch him, Dominic was arrested and was hit with sticks 200 times. When you are beaten by batons, you remove your shoes, your weapon, your military uniform, and you know that in Central Africa the sand is very hot, so you'd better follow Kony's orders."

The prosecution team, who interrogated the radio operator earlier this week (late January), asked him to authenticate a series of wire taps provided by Uganda's intelligence services. Using the taps transcripts, the prosecution emphasised that Ongwen enjoyed advantages brought by his commander position. According to the lawyers, Ongwen was allowed to have a mobile phone – an absolute prohibition within the LRA.

This is the first time one of LRA's fighters has been brought before a domestic or international court to stand trial. Over the past decade, Kony and his ragtag army have been chased from their northern Uganda base, but the ICC's most wanted man remains at large.