The Department for Work and Pensions has been criticised after one of its officials apparently submitted papers to a benefits appeal tribunal in which they called a disabled claimant a “lying bitch”.

The submission, formally rejecting an appeal by a disabled woman against the removal or downgrading of her personal independence payment (PIP) award, was made public by her outraged advice worker.

In an extract from the papers, the DWP official questions whether the claimant is genuinely entitled to carer’s allowance, a benefit for people who care for another person for at least 35 hours a week.

“In this lying bitches [sic] case she is receiving the mid-rate carers [sic] allowance component for providing day time supervision to another disabled person. The tribunal may wish to explore this further,” the official writes.

A welfare adviser posted a copy of the submission on the discussion boards of Rightsnet, a site for advice workers.

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The post says: “I have uploaded part of the DWP response to a PIP appeal by one of my clients. You may well recognise the usual cut and paste, but this one might inadvertently expose a canteen culture of contempt among many decision makers at the DWP.”

It adds: “I don’t know how this particular submission writer thinks they can get away with calling a claimant a ‘lying bitch’.”

Derek Stainsby, a rights adviser at Plumstead Community Law Centre, who made the extract public, told the Guardian the document was part of a routine bundle of papers sent by the DWP to his client, and copied to the tribunal service before a tribunal meeting to consider his client’s appeal.

He added that while he had seen an increase in general hostility towards claimants by the DWP in recent years, he had not encountered anything like this: “It’s the sheer contempt: I have never seen it go to these depths before.”

The post provoked discussion among fellow welfare advisers. One wrote: “OMG that is truly shocking, even by DWP standards.” Another wrote: “Obviously intended as an internal joke that was supposed to be edited out before being sent out, but instructive as to the true mindset [of the DWP], particularly as this was clearly meant to be shared with and approved of by colleagues.”

Another speculated: “Submission writer possibly the victim of a colleague’s prank? Get up to make cup of coffee. come back and finish document without checking back.”

A DWP spokesperson said it had not yet been able to verify the document, adding: “We do not comment on leaked documents. We expect the highest level of professionalism from our staff and any behaviour like this would be completely unacceptable. We would always take action where serious or gross misconduct was proven.”

Alan Markey, the chair of the National Association of Welfare Rights Advisers, told the Guardian: “It’s indicative of the culture of contempt towards disabled people in the DWP.”

There is widespread concern that PIP assessments, which are carried out by private firms on behalf of the DWP, are inaccurate and unfairly discriminate against mentally ill claimants. Nationally at least 70% of appeals against PIP decisions are successful.