Officials have refused to release a report they say cleared a minister of wrongdoing over a £5,000 donation from a secretive organisation.
DWP minister Guy Opperman referred himself for investigation after the Mirror revealed he’d taken a donation from a “dining club” linked to a firm for which he’d given speeches.
Ministers are forbidden from accepting payment for speeches on topics linked to their role in government.
A probe was launched into the payments by the Government Internal Audit Agency (GIAA) last year, with a report handed to DWP's most senior civil servant.
The top official said he was "satisfied" the speeches were "consistent with his role", and that there was "no evidence of any link" between the decision to give the speeches and the donation being made.
But the department has refused to publish the report, or explain the reasoning for clearing Mr Opperman.
Mr Opperman, then a pensions minister, took the cash sum from a group called the London and Northern Dining Club in October.
While MPs are required to name individual donors, a loophole exists to allow ‘dining clubs’ to give cash without having to declare their membership.
Millions of pounds worth of ‘dark money’ is given through such anonymous organisations.
Mr Opperman’s entry on the Register of Members’ Interests includes an address for the Club - a £700,000 riverside penthouse apartment in South London.
The apartment is owned by David Broome and Ozkar Yasar, who co-founded the Broome Yasar Partnership, an executive recruitment consultancy firm.
Mr Opperman spoke at at least three events hosted or co-hosted by the Broome Yasar Partnership between 2020 and 2022.
One event took place in February 2020, just weeks after the Government’s Pension Schemes Bill was introduced to Parliament.
At each event, public online posts reveal Mr Opperman spoke about environmental, social and governance (ESG) regulations - a part of his brief as Pensions minister - and a key part of the bill.
The Ministerial Code states: “Ministers should not accept payment for speeches or media articles of an official nature or which directly draw on their responsibilities or experience as Ministers.”
As a ‘members’ association’, the London and Northern Dining Club is not required to be registered anywhere, or declare any details of its members or leadership.
There is no suggestion of wrongdoing on the part of Mr Yasar or Mr Broome.
Mr Opperman said he did not believe he had broken any rules.
But after being contacted by the Mirror last January, he referred himself for an investigation.
He said: "This political donation has been declared properly and transparently in accordance with the rules and was not connected to events I attended as a minister.
"To ensure confidence, I have asked the department's permanent secretary to take an independent look into the facts."
A DWP spokesperson said: “The Government Internal Audit Agency has concluded its investigation into these matters.
"Having reviewed its report, the Permanent Secretary is satisfied the speeches made by the Minister for Pensions at the time were consistent with his role.
"He has seen no evidence of any link between the minister’s decision to give the speeches and the political donation received by his constituency party, which was properly declared."