The father of kidnapped p­hotojournalist John Cantlie has died, not knowing whether a video message he sent to his son's Islamic State captors had reached him.

Paul Cantlie, 80, lost his fight for life following complications after suffering pneumonia. In a statement, the family said: "Paul died not knowing whether John's captors had received any of the messages he had sent to them."

It said they had made "urgent" but futile attempts to contact John Cantlie to inform him of his father's death on Thursday.

Father-of-three Mr Cantlie's physical strength had been diminishing since his son's kidnap two years ago.

In an emotional video message from hospital, Mr Cantlie senior had told his son that he was "very proud" of his actions in wanting to report from Syria.

However, the family added that Paul Cantlie had "totally deplored what he and many others saw as an abuse of power by Tony Blair when the UK went into Iraq in 2003. With many others, he called for Tony Blair to be indicted for war crimes."

The Cantlies said the lack of any communication from his kidnappers following the messages had left Mr Cantlie senior feeling a "terrible sense of abandonment".

"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," he added.

The family added that their father's fortitude, quiet courage, humour and intelligence had been tested in recent times, but his determination was a beacon for the family "as they struggle with the realities they all currently face".

John Cantlie, from Surrey, has appeared from captivity in carefully scripted videos in which he criticises both the US and UK. His capture follows the killings of David Haines, 44, who was educated in Perth, and Alan Henning, 47, from Greater Manchester, both aid workers who were captured in Syria.

Their families joined together at the weekend to call for communities to rise above the terrorists.