A Syrian refugee who made headlines after he took a selfie with German Chancellor Angela Merkel is suing Facebook for its alleged failure to remove photos falsely linking him to terrorism.

19-year-old Anas Modamani took the pic of himself with Merkel in September 2015 at a refugee shelter in Berlin.

That image, along with others taken by press agencies, was widely used by media outlets and social media users to comment on Germany's response to the refugee crisis.

However, in at least three different cases his image was doctored by trolls in order to falsely link him to terrorism and crimes.

Modamani was mistakenly identified as one of the men responsible for the bomb attack at Brussels Airport last year. His image was Photoshopped on to a photo of the truck used in the Christmas market terror attack in Berlin along with the words "Es sind Merkels Tote" ("They are Merkel's dead"). And he was accused of being one of seven men who tried to set a homeless man on fire in Berlin.

Modamani disabled his Facebook account and hired attorney Chan-jo Jun to take a case seeking an injunction "to prevent Facebook from publishing the slanderous image of the Syrian refugee Anas Modamani in the context of terrorist attacks."

In the video below, the lawyer said the original post about the homeless arson case had been shared by around 500 people, and likely to have been seen by 25,000 to 50,000 people.

This isn't the first time Chan-jo Jun has taken on Facebook. In November 2016 he initiated an investigation against Mark Zuckerberg and other Facebook executives for failing to remove hate speech even once it was aware of the violations of German law.

Regarding Modmani, a Facebook representative said: "We received a takedown request from Mr Jun alleging that a specific item of content on our platform violates Mr Modamani's right of personality. Access to that reported content was quickly disabled, so we do not believe there is any basis for him to seek an injunction."