Islamic State leader Baghdadi sexually abused American hostage: Reports

Abu Bakr al-Baghdadi, the leader of the Islamic State (IS) group, repeatedly raped the late American hostage Kayla Mueller when she was in the group's custody, a US news report said on Friday.

US officials told ABC News that they had received the information from various sources, including two young Yazidi girls who were held for two months in the same house as Mueller in the Syrian town of al-Shadadiya.

Baghdadi would regularly visit the house to meet with Abu Sayyaf, a Tunisian IS financier, the US officials said. Baghdadi often brought Mueller into a private room to sexually abuse her.

One of the Yazidi girls was sexually abused by Baghdadi, while another was in a forced marriage to Abu Sayyaf, the report said.

Abu Sayyaf's wife, Umm Sayyaf, was in charge of the sex trade in which female captives were sold or given as "gifts" to IS fighters.

Mueller's family confirmed to ABC News that the US government had informed them that she had been sexually abused by Baghdadi, who considered her his property.

The revelation that she was sexually abused seems to contradict a letter written by Mueller, smuggled from captivity, that said she was "completely unharmed" and treated with "the utmost respect + kindness".

The fresh information about Mueller's ordeal shatters rumours that she cooperated or was a willing spouse, which had deeply upset her family, ABC said.

It said the details about Baghdadi's direct role in Mueller's abuse, in addition to being drawn from the US debriefings of two Yazidi teenage girls held as sex slaves in the Sayyaf compound, were confirmed by an interrogation of Abu Sayyaf's wife.

Mueller would have turned 27 on Friday.

Republican Senator John McCain, from the Muellers' home state of Arizona, has called on the government to explain why Sayyaf's widow was not extradited to the United States to stand trial.

Although the White House said Umm Sayyaf was "complicit" in Mueller's captivity, she was handed over to Kurdish authorities in Iraq. McCain questioned the reasons for her evading US justice.

The 26-year-old aid worker from Arizona was captured in August 2013 in Aleppo.

The IS group claimed in February that she had been killed in an airstrike by a Jordanian military plane in the Syrian city of Raqqa, the militant group’s self-proclaimed “capital”.

US officials have confirmed her death, but not the cause of death.

Mueller had volunteered in India, and was later an activist with the pro-Palestinian International Solidarity Movement (ISM) in the West Bank.