Jeremy Corbyn’s closest aide used his private email address to discuss Labour antisemitism cases with a senior official of the left-wing Unite union, the JC can reveal.

Leaked emails seen by the JC show Seumas Milne, the Labour leader’s director of communications, used his Gmail account in discussions with Andrew Murray, who himself used an email address belonging to Unite to curb an on-going dispute over Jew-hate involving a party member.

Labour’s current general secretary Jennie Formby was also in the email chain on a Unite address linked to her own former role as the union’s political director.

Other members of Labour’s compliance unit were then sent the advice of top officials who offered their own views on on-going antisemitism cases.

Mr Milne, who was appointed Labour’s Executive Director of Strategy and Communications in October 2015, is known to have hard-line anti-Zionist views and once spoke at a pro-Palestine rally in support of Hamas, saying: “It is not terrorism to fight back.”

Last week, the JC revealed how Mr Murray, chief political adviser to Mr Corbyn, had used a non-Labour Party email account to overrule a suspension of a Labour councillor who had denied that the notorious mural in Tower Hamlets which depicted Jewish bankers was antisemitic.

Mr Murray, whose daughter Laura is Labour’s newly appointed Head of Complaints, is a former Communist Party of Great Britain member who once argued Adolf Hitler is the most hated historical figure only due to the fact that his victims were “almost all white Europeans” rather than non-white people.

Dame Margaret Hodge, the veteran Labour MP who has repeatedly voiced her anger at her party’s failure to tackle anti-Jewish conduct, said: “Several sources have told me that Corbyn’s inner circle have long discussed complaints using private email addresses – knowing that this allows them to slip under the radar and avoid all scrutiny.

”It’s clear that Corbyn’s top team have been meddling and watering down discipline against antisemitic members, and have been trying to do so out of sight.”

Dame Margaret called for the Equalities and Human Rights Commission (EHRC) to “widen the scope of its investigation” into Labour to account for the use of email addresses outside of Labour’s servers for conversations relating to antisemitism.

Another senior Labour figure added: “Why on earth was Seamus Milne, Corbyn’s most trusted ally, using a private email address to discuss matters as important as allegations of racism within the Party?

“Either he wasn’t taking the allegations seriously enough to merit an official response – or perhaps he had got used to using a private email address for conversations he wanted to hide?”

Evidence of Mr Milne’s email exchanges with Mr Murray emerged after a submission sent by top legal firm Mischon de Reya to the EHRC on behalf of the Jewish Labour Movement.

Labour sources told the JC on Wednesday that both Mr Milne and Mr Murray had been contacted on private email addresses by Labour Party staff members who were seeking their advice on antisemitism cases.

But the exchanges appear to confirm growing speculation that senior Labour officials discussed issues involving racism, bullying and other areas of abuse outside of the perimeters of the party’s Governance and Legal Unit.

The JC understands that the EHRC is to write to Len McCluskey’s union within the next week and demand they had over any data related to the investigation into claims Labour was institutionally antisemitic.

Last week at a Commons Select t Committee hearing an EHRC official confirmed the organisation had powers to compel organisations to hand over information deemed to be relevant for an investigation.

Any attempt to delete emails or destroy other data would be considered a criminal act.

The JC has also learned that Labour has recently been warned by the Information Commissioner’s Office (ICO) that it has “infringed…[its] data protection obligations” after failing to hand over data relating to allegations of online hate and abuse requested by members.

One Labour member, who asked not be named, told the JC they had been at the centre of an online bullying campaign from pro-Corbyn left-wingers and had demanded to see some of the material used in an investigation by the party as part of a Subject Access Request (SAR). Labour refused to supply the information and the member complained to the ICO.

A statement issued by the ICO confirmed: “The ICO are aware that The Labour Party have a number of outstanding SAR requests and in this instance have failed to respond to your request within the statutory one month calendar deadline.

“We therefore consider the organisation to have infringed their data protection obligations in this instance.”

Labour sources said former staff members decided of their own volition to request support from Mr Milne, Mr Murray and others.

They said Labour staff in the Leader’s Office did not make decisions on cases and that only the Governance and Legal Unit had the authority to do so.

They said the emails were written before GDPR came into force in May 2018, so there was no data breach.

A Labour spokesperson said any allegation that personal email addresses were used to avoid scrutiny was "false and illogical".

They added:: "These emails, which were reported on and accounted for in March, are fully searchable and available on the Labour system."

On any allegation that Unite are involved in cases, a Labour Party spokesperson said: “This is baseless. Only employees, NEC and NCC members are involved in complaints.”