Media rights watchdog Reporters Without Borders has called for renewed efforts to secure the release of British photojournalist John Cantlie held by the Islamic State group on the fifth anniversary of his kidnapping.

Cantlie was taken near the Turkish border in northern Syria along with US journalist James Foley, who was beheaded by Isis in 2014.

“Today marks five long years that John Cantlie has been held in captivity,” said Rebecca Vincent, UK director for Reporters Without Borders, which is known by its French acronym as RSF.

She said Cantlie, who has appeared in a series of videos released by Isis, had been “deprived of his liberty, exploited and used for propaganda purposes”.

“We urge all relevant authorities to do their utmost to ensure that John and his family do not have to endure another day of this hell, and that he is immediately brought home safely,” she said in a statement.

Cantlie last appeared in a video in December 2016 in the Iraqi city of Mosul, which has since been recaptured from Isis jihadists.

In July 2017, RSF said there were unsubstantiated reports in Iraqi media that Cantlie had been killed in air strikes on Mosul.

In October, it said an Isis fighter had told French magazine Paris Match that he had seen Cantlie “seven or eight months ago” in Raqqa, the jihadists’ former stronghold in Syria.

Cantlie is one of around 22 journalists and media workers still believed to be held hostage by Isis, RSF said.

“Despite the fact that IS is losing ground in Iraq and Syria, there has been no information about the fate of these journalists,” the watchdog said. “RSF calls on local and international authorities to redouble their efforts to find them all.”

Iraq and Syria are ranked 158th and 177th respectively on RSF’s freedom index as among the world’s deadliest countries for journalists.