JUBA (Reuters) - A South African on trial in South Sudan could face the death penalty if found guilty of charges including conspiracy to overthrow the government and supplying weapons, his lawyer said on Tuesday, a day after his co-defendant was sentenced to death.

South African national William John Endley served as an advisor to rebel leader Riek Machar, whose forces have been fighting those loyal to President Salva Kiir in a civil war since 2013.

On Monday South Sudan’s High Court handed the death sentence to James Gatdet Dak, a former spokesman for Machar, as well as a combined 21 years for incitement and conspiracy against Kiir’s government.

The charges against Endley, a retired army colonel, that carry the death penalty are conspiracy to overthrow the government, espionage and supply of weaponry, his lawyer Gardit Abel Gar, told Reuters.

He has also been charged with insurgency, sabotage, terrorism and illegal entry into South Sudan, he said. The exact charges against Endley had previously been unclear.

South Africa’s Foreign Ministry did not respond to a request for comment.

The court adjourned Tuesday’s hearing to Feb. 15 after witnesses called by the defense did not appear.

“We were unable to get the witnesses. Some them are outside the country,” Abel said. The court was not giving the defense enough time to summon its witnesses, he said.

South Sudan, which won independence from Sudan in 2011, descended into civil war in 2013, months after Kiir fired his then deputy Machar. Tens of thousands of people have been killed and a third of the population have fled their homes.

Machar, who fled to Democratic Republic of Congo after fierce fighting broke out in Juba in July 2016, is now in South Africa.

Diplomatic and political sources say he is being held by South African authorities at an unknown location to keep him from participating in the conflict. Pretoria says he came to South Africa for medical treatment and was staying as a “guest of the government”.

A relative of Endley, who did not want to be named, said South African officials in Juba had worked hard to provide consular support but Pretoria could do more to push his case.

“They’ve helped us in getting money and parcels to him, but I think more could be done at the diplomatic level,” the family member said.

A ceasefire agreement signed between Kiir’s government and the rebels in December is intended to revive a 2015 peace deal which lasted less than a year before collapsing.

Talks on a new power-sharing arrangement and an election are scheduled to follow but clashes have continued to break out, prompting the United States to impose sanctions.

On Monday, the government accused rebels of launching attacks in the northeastern town of Nassir. An internationally backed ceasefire monitoring team said it was sending a team to investigate the violence in the next 24 hours.