An image posted online appears to show that ISIS captive Tomislav Salopek of Croatia has been beheaded, the SITE Intelligence Group said Wednesday.

Salopek was kidnapped July 22 in the area of Cairo, according to his employer and the Croatian government.

CNN could not independently confirm the authenticity of the image, and Croatian and Egyptian officials have not confirmed Salopek's death.

In a video distributed online August 5, a group claiming to be ISIS' branch in the Sinai Peninsula threatened to kill Salopek if Egypt didn't release female Muslim prisoners in 48 hours.

Read more HERE.