Supporters of the Islamic State of Iraq and Syria (ISIS) jihadist group circulated images on social media on Tuesday which they claimed showed a Jordanian hostage being burned alive.
The video released online showed images of a man purported to be Jordanian pilot Maaz al-Kassasbeh, who was captured by ISIS in December, engulfed in flames inside a metal cage.
Reuters said it could not verify the authenticity of the photos and video at this time.
The allegations come two days after ISIS announced it had beheaded Japanese hostage, journalist Kenji Goto.
An audio message that appeared to be from Goto last week said Kassasbeh would be killed if Jordan did not release Iraqi Sajida al-Rishawi, in jail for her role in a 2005 suicide bomb attack that killed 60 people in the Jordanian capital Amman.
Jordan had offered to free Rishawi, who was convicted for her part in triple-hotel bombings in Amman in 2005 that killed 60 people, if ISIS released Kassasbeh.
ISIS, which has declared a "caliphate" in territories seized in Syria and Iraq, has killed thousands of citizens and soldiers in both countries. It has particularly targeted ethnic and religious minorities, as well as foreign hostages, some of them in highly-choreographed videotaped sequences in which the victims are beheaded.