A dispute between Hamas's political leaders and military commanders is hindering mediation efforts to reach a prisoner exchange agreement with Israel, sources close to Hamas revealed over the weekend. The sources told The Jerusalem Post that one of the commanders of Hamas's armed wing, Muhammad Sinwar, is insisting that his brother Yahya be included in any prisoner swap. Yahya Sinwar is one the founders of Hamas's military wing and has been in Israeli prison since 1989 for his involvement in terrorism. The sources said that Muhammad Sinwar, who was directly involved in the abduction of IDF soldier Gilad Schalit in 2006, had threatened to harm him if his brother were not included in a prisoner exchange. Last week Hamas's political leaders informed the Sinwar family in Khan Yunis that their son would most likely be released from prison, but would be deported to Syria or another Arab country. The family has rejected the offer, insisting that Yahya Sinwar be allowed to return to his home in Khan Yunis. The sources said that Muhammad Sinwar's threats to harm Schalit had angered the Hamas leadership in the Gaza Strip and Syria. Damascus-based Hamas leader Khaled Mashaal was said, according to the sources, to have phoned Muhammad Sinwar to reassure him that his brother would be freed. Mashaal also promised to make sure that the brother was permitted to stay with his family in Khan Yunis when and if he's released. Sinwar's demand is believed to enjoy the full backing of Ahmed Ja'bari, overall commander of Izzadin Kassam, the armed wing of Hamas, the sources added. The row between the armed wing and the political leadership of Hamas was likely to complicate the mission of Egyptian and German mediators who had been working hard to forge a deal between the Islamist movement and Israel. Meanwhile, Hamas representatives gave conflicting statements regarding Mashaal's visit to Cairo over the weekend. Some said the trip was linked to efforts to reach a prisoner agreement with Israel, while others said it came in the context of Egypt's efforts to reconcile Hamas and Fatah. Hamas legislator Salah Bardaweel denied Arab media reports that Mashaal was in Cairo to finalize a Schalit deal. "The purpose of the visit is to find a way out of the impasse with regards to national dialogue [with Fatah]," Bardaweel said, stressing that his movement was keen on ending the conflict. Mashaal, who is heading a delegation of senior Hamas officials, held talks in Cairo with Egyptian General Intelligence chief Omar Suleiman. Ayman Taha, a Hamas spokesman in the Gaza Strip, said Mashaal's visit was also linked to efforts to reach a deal with Israel. He did not elaborate. But both Bardaweel and Taha confirmed that the Germans were "deeply involved" in efforts to reach a prisoner exchange agreement. They said that the Egyptians were exerting heavy pressure on Hamas and Fatah to end their differences and form a Palestinian Authority unity government.