Thomas Lubanga, the first person convicted by the International Criminal Court (ICC), will call two witnesses next month to provide additional evidence in support of his appeals against conviction and 14-year jail term.

According to an order issued Friday by the Appeals Chamber, ‘Witness D-0040’ and ‘Witness D-0041’ would testify on April 14 and 15 via video link from an undisclosed location.

In March 2012, Mr. Lubanga was found guilty of recruiting and conscripting children under the age of 15 and actively using them in an armed conflict in the Ituri region of the Democratic Republic of the Congo. The crimes were committed during 2002 and 2003.

In July of the same year, the trial chamber handed him a 14-year jail sentence. However, since he had already been in court’s custody for about six years, he would have to serve only an additional eight years.

At the end of 2012, Mr. Lubanga appealed against both the conviction and the sentence. He requested for permission to call two witnesses as part of the bid to have the conviction quashed.

The prosecution also appealed for the sentence to be raised on the ground of disproportion between the crimes and the sentence. At the sentencing hearing, then prosecutor Luis Moreno-Ocampo asked judges to hand down a maximum 30-year jail term but added that the prosecution could recommend a lower sentence if the accused apologized and promoted reconciliation in Ituri.

Article 81 of the court’s founding law, the Rome Statute, provides that a convicted person can appeal on any of these four grounds: procedural error, error of fact, error of law, or “any other ground that affects the fairness or reliability of the proceedings or decision.”

The grounds for Mr. Lubanga’s appeal include alleged breaches by the prosecutor of her duty to investigate, alleged breaches by the prosecutor of her disclosure obligation, and alleged factual errors with regard to the age of individuals who served in Mr. Lubanga’s Presidential Guard.

In their verdict, judges concluded that between September 2002 and August 2003, leaders of the Union of Congolese Patriots (UPC) and its armed wing recruited young people, including children under the age of 15, on both voluntary and coercive bases. The judges also found that Mr. Lubanga was the president and commander-in-chief of the groups and that he had child soldiers among his bodyguards.

Last January, appeals judges allowed Mr. Lubanga to add a new ground of appeal related to non-disclosure by the prosecutor to the accused of evidence that the defense deems exculpatory. The evidence, which comprises a list of names and photographs of UPC Presidential Guard members, is deemed relevant to the finding of the use of children under the age of 15 years in Mr. Lubanga’s personal guard.

The judges said the defense’s evidence related to the non-disclosure seeks “to call into question the reliability of a considerable part of the findings upon which Mr. Lubanga’s conviction was based.”

The hearing scheduled for April will also serve as an opportunity for parties and participants to make submissions before the chamber. The timetable and specific subjects to be addressed will be issued in due course.