Royal Bank of Scotland said on Monday there was no evidence it had deliberately caused SMEs to fail, while a senior British lawmaker called for the country's regulator to fix a publication date for a long-delayed review into the allegations.
The Financial Conduct Authority (FCA) announced the review in January 2014 into how the bank's Global Restructuring Group (GRG) treated business customers during and after the 2007-09 financial crisis, when taxpayers had to rescue the lender.
Earlier, the BBC and BuzzFeed News reported that documents leaked by a whistleblower supported allegations that RBS tried to profit from struggling businesses in a "dash for cash" by bank staff.
"The leaks today illustrate the need for the FCA to get on with publication as soon as possible. I will be writing to the FCA for a publication date," Andrew Tyrie, chairman of parliament's Treasury Select Committee, said in a statement.
"The basis of what has come out so far, this appears to be a shocking story, with many businesses at the wrong end of it."
The FCA review, partly based on findings from consultants Mazar's and Promontory, was due to be published by the end of 2015. The regulator said earlier this month it has received the consultants' final report, but needs to complete a number of steps before it can publish the overall findings.
"This has been a complex and lengthy review ��� it is therefore important that we do not rush the final stages of this process," the FCA said on its website.
RBS said it had let down some small business customers and that it should have done better in some areas, but said investigations had no shown any wrongdoing on its part.
"We have seen nothing to support the allegations that the bank artificially distressed otherwise viable SME businesses or deliberately caused them to fail," RBS said.
RGL Management Ltd, set up to launch a GRG-related group action against RBS in early 2017, said it expects to act on behalf of more than a thousand businesses with an aggregate claim size reaching billions of pounds.
Meanwhile, Collyer Bristow, a law firm, said the FCA should set up an independent compensation scheme so that customers can avoid the cost of going to court.
(Reporting by Huw Jones and Andrew MacAskill; Editing by Alexander Smith)