A South Sudan army general is facing charges of treason for allegedly plotting a rebellion against President Salva Kiir's government.

The trial of Major-General Stephen Buoy Rolnyang began on Monday before a seven-member military court after he was charged with offenses related to insecurity and disobeying military orders, the East African reported.

Rolnyang was arrested last May in northern Mayom, after defying military orders to report to army headquarters in Juma, the capital of Jubek State.

However, he defied those and together with the troops in his division unilaterally moved to Mayom, in Unity State – a move interpreted as a defection to wage rebellion.

"It is the prerogative of the commander-in-chief and the chief of defence forces of the army to see to it that justice must be done in cases related to insecurity," said Brigadier General Santo Domic.

The trial has been postponed to Thursday following Rolnyang’s defence team alleging that the military men on the court panel were of inferior rank and experience to their client.

The case is unusual in that the major-general is only the second senior military personnel member to go on trial in the war-torn country since the conflict between the government and the opposition broke out in 2013.

In early 2014 a high court in the capital Juba tried four senior generals, who were also politicians, for treason. They were later pardoned and released without sentencing.