A Jewish-German comedian has spray-painted 30 undeleted hate tweets onto the pavement outside Twitter’s Hamburg headquarters.

Shahak Shapira carried out the protest after the company refused to remove the racist, homophobic and antisemitic material despite having been notified about the content over a six-month period.

He used stencils to leave the abusive messages on the street in front of the social media company’s offices last Friday morning. Comments included “Judenschwein” (Jewish Pig), “N****rs are a plague to our society”, “Let’s gas some Jews together”, “Gays to Auschwitz” and “We need a final solution for Muslims in Germany”.

In a video of his latest project, Mr Shapira said that he had reported “about 450 hate comments to Twitter and Facebook” in the last six months.

“The statements I reported weren’t just plain insults or jokes, but absolutely serious threats of violence… things no-one should say and no-one should read”, he added.

He said that he had sent around 150 comments to Facebook, which removed around 80 per cent of them within a couple of days. Of more than 300 tweets reported to Twitter, however, Mr Shapira said he “received only nine answers… each of them stating there was no violation of Twitter’s rules.

“That’s it. All other reports were left unanswered. So I thought, ‘ok, if Twitter forces me to see those things then they’ll have to see them too’.”

Mr Shapira took 30 of the worst tweets and sprayed them onto the street outside the office. To enter the offices, employees would have to walk through the area painted with the tweets, and, as Mr Shapiro put it “they’ll have to look at all the beautiful tweets their company likes to ignore so much”.

The display, which covered a large part of the street on which the Twitter offices are based, attracted a lot of attention. The police showed up, but left again soon after, making no arrests.

“This will never be big enough to even visualise the amount of hate tweets on Twitter, but maybe we can at least give them food for thought”, Mr Shapira said.

Mr Shapira made headlines around the world in January after another project of his, “YOLOcaust”, took pictures which people had shared of themselves behaving in a disrespectful manner at the Holocaust memorial in Berlin, and photoshopped the people into actual photos showing Holocaust victims. The people in the photos could have their pictures removed from the YOLOcaust website, but only if they sent Mr Shapira a message asking him to “undouche me”.

Later on Friday morning cleaners removed the tweets right outside the entrance to the property, but left the vast majority of tweets which were in the surrounding area.

Mr Shapira said this action “fits well with Twitter’s policy of cleaning in front of their front door and leaving the rest to be someone else’s problem.”