Glyn Secker, the secretary of the Jewish Voice for Labour group, has been readmitted to the Labour Party after he was suspended over his membership of a secret Facebook group in which antisemitic material was posted.
Mr Secker was suspended as part of “disciplinary processes” after revelations about the group, Palestine Live, were published last week by researcher David Collier.
The party took action after Mr Collier’s investigation showed details of antisemitic posts and discussions on the Facebook group.
There is no sugesstion that Mr Secker posted anything antisemitic in the group.
Members of the group included Jeremy Corbyn, who left shortly after being elected Labour leader, his son Seb, Baroness Tonge, former Channel 4 presenter Paul Mason, and Labour MP Clive Lewis.
Shoah-denier Paul Eisen and antisemite Gilad Atzmon also belonged to the group.
A letter headed “Lift in your Administrative Suspension from the Labour Party” was sent to Mr Secker on Monday by Sam Matthews, Labour’s head of disputes.
It stated: “As you aware, on the 7th March 2018 the Labour Party wrote to you to administratively suspend you from the Party.
“This action was taken in light of the publication of the report into the Palestine Live Facebook group. It was important that the allegations relating this group were investigated.
“Having fully reviewed the evidence available to the Party, it would not be in the Party’s interests to pursue further disciplinary action in relation to this matter.
“Your administrative suspension has therefore been lifted.”
Mr Secker was told he had been suspended because it was “necessary for the Party to take swift action in relation to those members who may have been implicated in breaches of the Party’s rules”.
The 74-year-old said he had no memory of joining the group and was not aware at first as to the reason for his suspension.
He told the JC: "It was only after I read an article about the Facebook group in the Guardian did I put two and two together and realise my suspension must have something to do with that,"
"When it comes to Facebook I’m not an expert. I'm of a generation that is not great on these things."
He said he was shocked by the antisemitic content found in the group.
"Some of the stuff up there is disgusting. The person who runs the group should be managing it better and taking down racists posts. It is irresponsible and it is naïve to leave it up there where hundreds of people can see it. I would never try to defend those posts - how could I.
"If it were posted on my Facebook I would challenge it and I would take it down," he said.
It is not yet clear whether the review of the evidence cited by Mr Matthews includes a probe of all Labour Party members in the group, or only selected individuals.
Labour has been contacted for comment.
In 2010, Mr Secker, a leading member of Jews for Justice for Palestinians, captained a boat aimed at reaching Gaza and breaking an Israeli naval blockade of the port.