The Palestine Solidarity Campaign was once again the focus of allegations of anti-Semitism this week, after the publication of a 79-page report into online comments by its members across the country.

Only last week, the London-based organisation was forced to tell supporters with anti-Semitic views that they were “not welcome,” after a spate of hateful messages were left as comments on the PSC’s Facebook page.

Now, a report by activist and blogger David Collier has unearthed dozens of reported examples of anti-Semitic comments by PSC members on social media.

Among the examples Collier lists are PSC members sharing anti-Semitic articles, comments and posts. Some allege that Israelis are harvesting organs. Others suggest Israel’s intelligence service Mossad was behind U.S. terrorist attacks, or that Israel is secretly helping Islamic State (ISIS) wage war on its borders.

There are familiar themes in many of the comments Colliers lists as examples, including the conspiracy theory that Jews control the world, with hashtags such as #jewnitedstates shared. Others common tropes liken Israeli policy to the policies of Nazi Germany.

Collier, who infiltrates pro-Palestinian events “undercover,” said PSC members “frequently cross the line between legitimate criticism of Israel and accusations that can be identified with classic anti-Semitic tropes”.

He writes: “Rabid conspiracy theory, global Zionist control, rabid antisemitism, numerous links to neo Nazi sites, right wing fascist think tanks and of course holocaust denial… The foot soldiers of the Palestine Solidarity Campaign.”

The PSC has taken a hard line against members and supporters making anti-Semitic comments, and has been credited for acting swiftly in recent months, when concerns have been raised.

The organisation has repeated it “vigorous opposition to anti-Semitism and racism of all types,” adding: “As an organisation we are very clear that anti-Semitism has no place anywhere in our campaign for Palestinian human rights.”

The PSC has been approached for comment.