THE FATHER OF British Islamic State hostage John Cantlie has died.

The Guardian has reported that Paul Cantlie (81) died following pneumonia-related complications.

Earlier this month, he had made an impassioned plea calling for his son to be released by the militant group.

To those holding John, please know that he is a good man. He sought only to help the Syrian people and I ask you for all that is sacred to help us and allow him to return home safely to those he loves and those who love him.

John, a British photojournalist, has been held prisoner by Islamic State for almost two years.

John Cantlie poses with a Free Syrian Army rebel in Aleppo on 11 November 2012. AP / Press Association Images AP / Press Association Images / Press Association Images

In a statement released by the Cantlie family, they said that Paul “died not knowing whether John’s captors had received any of the messages he had sent to them”.

The failure of communication to date has inevitably led to a terrible sense of abandonment, particularly for John’s father, with the family feeling ignored.

This burden has been especially hard these last few days, as we have so needed to tell John that his father, whom he so loved, has died.

In a video released in September, John said he had been “abandoned” by the British Government and warned that the West faces “another Vietnam” in their war with the Islamic State.

Members of the jihadist group have beheaded a number of civilians in recent months, including British aid worker Alan Henning and American journalist James Foley.

Explainer: What is happening with the Islamic State group?

Read: Islamic State group posts video of British journalist claiming he has “been abandoned by my government”