Christian Solidarity Worldwide (CSW) has reported that both Revd Yat Michael and Revd Peter Reith are being held in separate cells in Kober Prison and chained up on a daily basis.
The two men, from the Presbyterian Evangelical Church, have been accused of undermining the constitutional system of the Sudanese Penal Code; waging war against the state; disclosure and receipt of official information or documents; arousing feelings of discontent among regular forces; breach of public peace; and offences relating to insulting religious beliefs.
Two of the charges carry the death penalty or life imprisonment in the event of a guilty verdict.
CSW have told Premier that since being moved to Kober Prison, a high security facility in Khartoum North, the pastors have not been allowed to receive visitors.
But they were allowed to meet with their wives and legal representatives at court on 15th June, the first time they have been able to do so in around two weeks.
Questions over the pastors well-being have been raised following the harsh conditions that they're being held in.
Revd Yat Michael travelled to Khartoum in Sudan for medical treatment in December 2014, the day before his arrest, and has not seen relevant medical professionals since.
During a June 15th hearing the prosecution presented evidence from a National Intelligence and Security Service (NISS) officer.
The next hearing is set for June 18th, when it is anticipated the prosecution will conclude its case.
Mervyn Thomas, Chief Executive of CSW, said: "We reiterate our call to the Sudanese authorities to regularise the detention of Rev Michael and Rev Reith.
"The continued refusal to allow legal visits at Kober Prison and the conditions in which the pastors are being detained are in violation of their right to a fair trial, as articulated in Article 14 of the International Covenant on Civil and Political Rights (ICCPR), to which Sudan is a party.
"Furthermore, the fact that pastors are being chained amounts to degrading treatment, a violation of Article 7 of the ICCPR. We urge the Sudanese authorities to reinstate legal and family visits and to move the pastors to an appropriate facility.
"We also call for immediate and unfettered access to medical treatment for Rev Michael, in order to address his pre-existing medical condition, and urge the international community to hold Sudan accountable for any deterioration in his condition if access continues to be hindered or denied."
