The Global Restructuring Group (GRG) unit deals with RBS's corporate clients who find themselves in financial distress and have missed or are in danger of missing debt repayments. It is meant to work with companies to help them return to health.

RBS's Deputy Chief Executive Chris Sullivan and GRG head Derek Sach told the Treasury Select Committee that the division was not used as a "profit centre" when they gave evidence in June, contradicting the findings of a report by former Bank of England Deputy Governor Andrew Large.

However, in a letter to committee chairman Andrew Tyrie published on Tuesday, Sullivan said RBS now accepted Large's description.

"With regard to the term of 'profit centre' we wish to make clear we do not disagree with the way that that accounting term was used by Andrew Large in his report," Sullivan said in the letter.

Tyrie said RBS had made a "belated U-turn", having initially branded the description as "totally inappropriate".

"It now appears that RBS has been wilfully obtuse with the committee. If this is how RBS deals with a parliamentary committee, how much can customers and regulators rely on it to be straightforward with them?" he said in a statement.

Tyrie said he would be writing to RBS Chairman Philip Hampton on the matter and the committee would report on it after the summer.

RBS declined to comment on Tyrie's remarks.

Former government advisor Lawrence Tomlinson last year accused RBS of pushing small businesses into the GRG unit so it could charge higher fees and take control of their assets. An independent review by law firm Clifford Chance found no evidence the bank had set out to defraud customers, but the unit is still being investigated by Britain's financial regulator.

(Reporting by Matt Scuffham; Editing by Pravin Char)