After months of wrangling, MPs have released a report by the financial regulator which said a unit of RBS mistreated thousands of small firms.
The Global Restructuring Group (GRG) was marketed as an expert service that could save a business, but according to the report took "inappropriate" action.
Nicky Morgan, chair of the Treasury Committee, said the findings in the report were "disgraceful".
RBS said it was "deeply sorry" for its treatment of businesses in the GRG.
The contents of the report were first disclosed by the BBC in August last year.
The Financial Conduct Authority (FCA) had refused to publish the report, blaming legal reasons, but after a meeting, MPs on the Treasury Committee voted to publish it.
Ms Morgan said MPs had not taken the decision to publish lightly, as normally such reports are confidential.
However, she said there was an "overwhelming" public interest in its publication.
"The findings in the report are disgraceful. The overarching priority at all levels of GRG was not the health and strength of customers, but the generation of income for RBS, through made-up fees, high interest rates, and the acquisition of equity and property," she said.
The GRG operated from 2005 to 2013 and at its peak handled 16,000 companies.
Companies were referred to it when they skipped a loan repayment or suffered a significant drop in sales or profits.
The report estimated that about a third of firms transferred to GRG were not viable.
Of those that may have been able to continue trading, the FCA found that one in six had actually been damaged by GRG.
Some customers had interest charges raised or were hit with new fees.
"Our central conclusions are that there was widespread inappropriate treatment of customers by GRG," the report said.
It blamed "fundamental failings" in the management of the unit.
In particular, it says GRG put its own commercial interests ahead of the small and medium-sized firms it was looking after.
However, the report said that RBS did not move customers into the recovery unit for "inappropriate reasons".
An RBS spokesperson said: "We are deeply sorry that customers did not receive the experience they should have done while in GRG.
"Although the most serious allegation - that we deliberately targeted otherwise viable businesses in order to distress and asset-strip them for the bank's profit - has been shown to be without foundation, we know that the bank got a lot wrong in how it treated some customers in GRG during the financial crisis.
"The culture, structure and way RBS operates today have all changed fundamentally since the period under review and we have made significant changes to deal with the issues of the past, including how we treat customers in financial distress.
"We have accepted all the relevant recommendations from the report and our focus is now on rebuilding trust and supporting our customers."