Syrian television presenter Mohammed al-Saeed, kidnapped from his Damascus home in mid-July, has been executed, the Syrian Observatory for Human Rights said on Saturday.

"The television presenter, a well-known figure on state TV, has been executed, and the Al-Nusra Front has claimed responsibility for the killing," the Observatory's Rami Abdel Rahman told AFP.

Al-Nusra, a little-known Islamist armed group currently operating in Syria, claimed the kidnapping and execution of Saeed in a statement on Friday.

"The heroes of western Ghouta (in Damascus province) imprisoned the shabih (pro-regime militia) presenter on July 19," Al-Nusra's statement read. "He was then killed after he had been interrogated."

Posted on a forum featuring the Al Qaeda flag, Al-Nusra's statement showed a photograph of Saeed looking frightened, with his back against a wall in an unknown location.

"May this be a lesson to all those who support the regime," it said.

Last month, international media rights watchdog Reporters Without Borders issued a statement on Saeed's kidnapping, and urged his captors to release him.

"News media and journalists, both professional and citizen journalists, should not be targeted by any of the parties in a war or civil war," it said at the time.