Baroness Tonge is being investigated by the Commissioner for Standards in the House of Lords.

The independent peer was suspended and subsequently quit the Lib Dems in October after chairing a meeting at which an audience member compared Israel to Islamic State and suggested Jews were responsible for the Holocaust.

It has now emerged that she is the subject of an inquiry by the Commissioner for Standards over “alleged failure to act on personal honour and alleged breach of rules on House facilities”. The findings are expected to be published early next year.

The Commissioner’s Office would not offer any further details about the probe and it is not known whether it is connected to the event she chaired, which was organised by the Palestine Return Centre. The event hosted by Tonge marked the launch of a campaign calling for an apology for the Balfour Declaration.

She later insisted she didn’t hear much of the “rant” and claimed challenging such ranters only caused them to “go on and on”.

Simon Johnson, Chief Executive of the Jewish Leadership Council, said: “We welcome this investigation by the Commissioner of Standards.  It is entirely right that Baroness Tonge’s divisive and irresponsible use of House of Lords premises to host hateful events such as that of the Palestine Return Centre should receive proper scrutiny by the appropriate authorities. We will be interested in the outcome of the investigation”.

A spokesperson on behalf of the All Party Parliamentary Group Against Antisemitism said: “Members of the APPG were concerned to read reports of antisemitic comments spoken during a meeting in parliament and took appropriate action”.

Tonge has sat as an independent since resigning the whip in 2012  after claiming Israel would not exist forever in its president form – but remained a party member until the latest controversy.