US journalist beheaded in Syria

A gruesome video has been posted online of James Foley being beheaded by ISIS militants in Syria.

US Journalist James Foley in Syria in 2012. Picture: Manu Brabo/www.freejamesfoley.org

JOHANNESBURG - The family of American journalist James Foley say they have never been prouder of him and believe he has given his life to expose the suffering in Syria.

A gruesome video which has been posted online is busy being verified, but it's believed it shows Foley being murdered and beheaded by members of the radical group ISIS.

The 40-year-old US journalist had been missing in Syria since 2012, having survived six weeks in the clutches of pro-Muammar Gaddafi forces in Libya.

While in Libya, Foley said he witnessed South African photojournalist Anton Hammerl being gunned down in the desert, but was unable to help because he was taken captive.

After the video emerged on Tuesday, Foley's family have asked for privacy to 'mourn and cherish' a man they describe as an 'extraordinary son, brother and journalist'.

Meanwhile, CNN's Nic Robertson says Foley isn't the only journalist that this militant group has held hostage.

"They're holding more journalists, James isn't the only one. There are three other Americans, two British and one New Zealander. This speaks to ISIS using these people as bargaining chips to try to get what it wants and right now it wants the United States off its back."