The financial watchdog declined to publish the report because “it has not proved possible to obtain the consents” necessary for publication.

Instead, the FCA has sent a copy to the committee for publication.

The report investigated the actions of the Global Restructuring Group (GRG) – a RBS support unit for troubled businesses during the financial crisis.

A version of the 361-page investigation was leaked online on 12 February, which was subsequently viewed widely.

In the full, unredacted copy – GRG was found to be responsible for “endemic” mistreatment of SME businesses already in financial distress.

Andrew Bailey, chief executive of the FCA, had previously argued that publication was prevented by legal requirements for consent and to provide a right of reply to all persons involved in the report.

In a letter to the Treasury Committee, Bailey wrote: “We agree that it is regrettable that the report has been leaked, but this does not allow us to publish.

“We would be breaking the law if we were to publish the report without the necessary consents.”

Parliament orders

Earlier this week, Nicky Morgan MP, chair of the Treasury Committee, ordered the FCA under parliamentary privilege to publish the report by 16 February or send the committee a copy, warning that non-compliance could result in the FCA being found “in contempt of parliament”.

The committee will now meet when parliament returns on Tuesday 20 February, where Morgan has confirmed she will be asking members to agree to publish the report in full “as soon as possible”.

Bailey added: “As I hope you will understand, as a public body we regard it as vital to assist the committee as far as we can while respecting the requirements of the law.

“I do want to make clear that it is not our intention to frustrate or impede the work of the committee, quite the reverse in fact.

“It is very important to us that those companies that have suffered loss as a result of how they were treated whilst in GRG are appropriately compensated.”