Oct 21 (Reuters) - Mr Paul Cantlie, the father of British Islamic State in Iraq and Syria (ISIS) hostage John Cantlie, has died of "complications following pneumonia", his family said, according to several media sources.

Earlier this month, speaking from a hospital bed through a voice box, 81-year-old Mr Paul Cantlie called on ISIS to allow his son to return home safely. The group has already beheaded two American journalists and a British aid worker. Mr John Cantlie, a photojournalist, was captured in northern Syria in Nov 2012.

His father said the family had tried to contact his abductors but had received no response. At the time of his death, the senior Cantlie had received no update on whether his son's captors had received the message he had sent to them, the Cantlie family said, according to the BBC and several other media sources including the Daily Mirror.

The statement released by the family said the failure of communication had led to a "terrible sense of abandonment, particularly for John's father". The statement also said the family had made "urgent attempts" to contact Mr Cantlie since the last few days to inform him of his father's death.

Mr John Cantlie appeared in a video released by ISIS in September saying he would soon reveal "facts" about the group to counter its portrayal in Western media.

His father had said: "For the first time in almost two years, we saw John when he made a televised broadcast during which he told viewers that he was still a prisoner of the Islamic State and that maybe he will live and maybe he will die."