Her Majesty's Revenue and Customs have been criticised after documents appeared to indicate officials refused to raid the offices of a firm suspected of laundering huge sums of money in part because they donated money to the Conservatives.
Officials at HMRC last year rebuffed a request from French authorities to assist an investigation into telecoms giant Lycamobile over its financial activities.
The refusal noted that the firm was the “biggest corporate donor to the Conservative party led by prime minister Theresa May and donated 1.25m Euros to the Prince Charles Trust in 2012", according to BuzzFeed News.
The letter from HMRC also noted that Lycamobile was a huge company with “large assets at their disposal” and would be unlikely to agree to a raid and might respond with a legal challenge.
It said the French may not have provided enough "solid information" against the firm to warrant such a raid.
When first contacted by BuzzFeed, a spokesman for HMRC said: "No HMRC official would ever write such a letter. This is the United Kingdom for God’s sake, not some third world banana republic where the organs of state are in hock to some sort of kleptocracy."
But when shown a copy of the note, they said the inclusion of the reference to the Tories was "regrettable".
The spokesman added: "We never take political donations into account when working out how to work with other countries, or indeed on our own, in enforcing the tax law...
“But I can see how this is open to being read that way, which is why that should not be in there."
The spokesman insisted the information about donations had been included a "background" details about the firm.
"The application contained insufficient detail to satisfy the legal requirements to secure a warrant.
"After the French request was rejected, HMRC continued to liaise with the French authorities to explain the statutory requirements for a UK search warrant, and offered to meet the French Judge face to face to explain those requirements.
"HMRC always investigates suspected rule breaking professionally and objectively and is never influenced by political considerations. The facts speak for themselves: last year alone we secured an additional £8bn in tax from the largest businesses by tackling avoidance, evasion and non-compliance."
Public Accounts Committee chair Meg Hillier vowed to question HMRC about the claims later this month.
“The size of a company or its connections should not have any bearing on whether HMRC go in and do an investigation,” she told BuzzFeed News..
“I think they should explain to the British taxpayer what their rationale was for refusing the request.”
Nicky Morgan, the chair of the Treasury Committee, added that this “raises all sorts of questions and is completely inappropriate”.
She added: “I would expect the committee to look into this as part of our economic crime review and to have some early questions for HMRC about the correspondence that they sent.”