A Washington DC burger chain has apologised for its use of an image of a photojournalist beheaded by Isis in a tweet advertisement.

Z-Burger had put an image of slain reporter James Foley, who was captured by Isis in 2012 while covering the conflict in Syria. A video of his brutal 2014 murder was distributed by the group.

Chain owner Peter Tabibian took the tweet down and said in a statement: “An apology has been sent to some of you from a contracted marketing company over an unfortunate incident, a post in very poor taste that was not approved by me before being uploaded to our Twitter account”.

On 21 July the company's Twitter account posted an advertisement with an image of Mr Foley wearing an orange jumpsuit and kneeling facing the camera with a member of Isis wearing a full mask over their face. It was superimposed with an image of two hands holding a burger.

The tweet read: When you say you want a burger and someone says okay lets hit McDonald’s" accompanied by an emoji of eyes. The caption of the photo read: "You disgrace me".

The reaction on social was swift and harsh, as expected and Mr Tabibian issued an apology later that day.

(Screenshot/Twitter ) (Screenshot/Twitter)

Mr Tabibian wrote that he had "taken immediate steps to ensure that this never happens again". He also provided his email address for customers to contact him about the matter or any other issues.

The owner said the "inappropriate and offensive" advertisement was posted by Valor Media, a firm Z-Burger uses for social media promotions.

That company is run by Michael Valor, 23, a so-called social media influencer who also posted an apology on Twitter in the form of a series of videos.

"This was a Valor Media issue. Not an external issue from [Z-Burger]," Mr Valor said in the first video.

The self-professed "young gun" claimed the company had an "influx of volume" in the work the company received in the two weeks before the offensive advert was posted and said they "pulled on a new art director to the staff" who was to blame.

The tweet was taken down quickly but not before Mr Foley's mother, Diane Foley saw it.

She responded on Twitter via the James Foley Legacy Foundation's account, writing that she was "very saddened" by the image and its use as an advertisement for hamburgers.

But, she noted she "looked forward" to the promised donations to the charity by Mr Tabibian and Mr Valor. The foundation advocates for safe return of Americans captured abroad, particularly independent journalists covering conflicts who do not have the support of a full news organisation, and educates the public on threats to freedom of the press.