Breitbart News is being sued by a photojournalist who accuses the far-right news site of repeatedly using his photo of protestors without permission.

Terry Sylvester took the photo of a group of African-American students holding a Black Lives Matter sign and a bullhorn at a Berkley student protest in 2015, according to a lawsuit filed on Tuesday in US District Court in Washington DC.

Mr Sylvester, a freelancer photographer based in Michigan, claims the controversial online publication deliberately “copied and posted” the copyrighted photograph to Breitbart.com to accompany a number of articles on a range of topics.

The complaint reads: "Plaintiff [Sylvester] is informed and believes that Defendant [Breitbart], without the permission or consent of Plaintiff, has copied and used the Copyrighted Photograph. In doing so, Defendant violated Plaintiff’s exclusive rights of reproduction and distribution. Defendant’s actions constitute infringement of Plaintiff’s copyright and exclusive rights under copyright”.

The ultra-conservative site, which was unashamedly pro-Trump during the presidential election, is thought to have had nearly 2,600 advertisers sever their ties with it in recent months.

Last month, Sleeping Giants, a Twitter account that tracks advertisers for the publication and pressures companies into cutting ties with media they consider racist and sexist, said the number of ads who have pulled ads from Breitbart is “climbing towards 2600”. The group is part of a burgeoning grassroots campaign to boycott the platform amid mounting political tensions in the US.

Iran's 'Trumpism' contest Show all 10 1 /10 Iran's 'Trumpism' contest Iran's 'Trumpism' contest A picture taken on July 3, 2017 shows a cartoon of US President Donald J. Trump and First Lady Melania Trump on display at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian cartoonist Hadi Asadi poses for a picture with a trophy and an award next to cartoons of US President Donald J. Trump, at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranians look at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian reformist cleric Mahmoud Doaei looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian man looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian reformist cleric Mahmoud Doaei looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images

Breitbart, founded by conservative commentator Andrew Breitbart in 2007, has been implicated in a steady slew of controversies and has published a number of falsehoods, conspiracy theories and deliberately misleading stories.

During the 2016 presidential election, it promoted conspiracy theories about Hillary Clinton and her staff such as the totally baseless and spurious Pizzagate conspiracy theory which falsely alleged a Washington pizzeria was the home of a child sex abuse ring that included people such as Ms Clinton and her then campaign chief John Podesta.

Breitbart’s content has been called misogynist, xenophobic and racist and The New York Times has described its journalists as "ideologically driven”. Comment pieces published on the site include “Political Correctness Protects Muslim Rape Culture” and “Birth Control Makes Women Unattractive and Crazy”.

Steve Bannon, the former executive chair of Breitbart News which he described as “the platform for the alt-right” last year, was fired as President Trump’s White House Chief Strategist last month. He returned straight to be head of Breitbart and the site proclaimed the return of their “populist hero” on its homepage hours after his departure became public.

Breitbart News aligned itself with the European populist right and American so-called “alt-right” - a political movement which has been accused of racism, anti-semitism and misogyny - under the management of Mr Bannon who took the reigns around four years ago.