The profile is followed by more than 650,000 users on the social network – and usually posts upbeat and motivational updates.

Sunday’s messages, which have since been deleted, called for violence against Jews, insulted Donald Trump, and referred to alleged files related to Jeffrey Epstein.

In a statement, Sesame Workshop said the X account has now been secured – and described the posts uploaded to Elmo’s page as “disgusting”.

This is the latest controversy to befall Elon Musk’s platform in recent days.

Last week, X’s AI chatbot Grok also produced content with antisemitic tropes, which were later removed and denounced as “inappropriate”.

Musk purchased the website, formerly known as Twitter, back in 2022 – with extremist content increasing against a backdrop of less moderation.

The Anti-Defamation League, a US organisation that fights antisemitism, said: “It’s appalling that Elmo’s official account, known for spreading kindness, was hacked solely to spread violent antisemitism.”

“Antisemitism on social media fosters the normalisation of anti-Jewish hate online and offline – and contributes to an increasingly threatening environment for Jewish people everywhere.”

Elmo’s account has not posted since the hack.