Member of Corbyn's office intervened to block suspension of Labour member who was later arrested

She has been released pending further investigation.

The Sunday Times revealed Andrew Murray, Ms Murray's father and Mr Corbyn's political adviser, was copied in and responded to support his daughter's email, saying: "These recommendations have been endorsed by [party general secretary] Jennie Formby.”

But there followed a period of inaction from Corbyn's office which prompted a series of emails from Emilie Oldknow, the party's then-executive director, in which she pleaded for a decision on all the suspensions she recommended otherwise "people [will be] saying we are soft on anti-semitism or not acting."

It is the latest in a series of stories that disprove what Jeremy Corbyn told Jewish community leaders last year: that his office did not intervene in disciplinary cases.

Ms Murray's insistence that the member's posts were merely anti-Israel, rather than anti-Jewish, echoes an intervention by Corbyn ally Thomas Gardiner, the party's then head of complaints, at around the same time.

Mr Gardiner intervened to stop the suspension of activist Kayla Bibby, who posted an image from a far-right website of an alien branded with the Star of David suffocating the Statue of Liberty.

He said in an email the image was "anti-Israel, not anti-Jewish".