Facebook has been letting advertisers target people interested in the topics such as “Jew haters” and “how to burn Jews,” an investigation has revealed.

The social media giant removed several anti-Semitic ad categories when approached by investigative news group ProPublica, who had shown how ad buyers can pay £30 to target these people.

Journalists even showed how Facebook suggested how to expand the target group, such as by increasing the audience to those who ‘like’ guns rights.

The categories were available to advertisers buying ads through the firm’s self-service function, and journalists were able to use the system to target nearly 2,300 users who had previously searched by such terms and phrases.

The revelations will prompt further questions as to its business model and ethical controls. Facebook said algorithms create the categories, and that it would now be considering how to change its system to improve monitoring and avoid abuse.

Rob Leathern, product management director at Facebook, sait it had “removed the associated targeting fields”, adding: “We know we have more work to do, so we’re also building new guardrails in our product and review processes to prevent other issues like this from happening in the future.”