Ulster Bank parent company Royal Bank of Scotland's hopes of putting another major scandal to rest may be upended by a small business group that wants to see executives held to account.
The SME Alliance - a small business group that lobbies for fair treatment by banks and advisers - is launching its own investigation into the treatment of small firms by the bank's now-defunct Global Restructuring Group (GRG).
Efforts are being led in part by Nikki Turner, an SME Alliance director who is well-known for a separate report in 2009 credited with helping uncover fraud at HBOS in Reading.
That case led to corrupt financiers being jailed over a £245m loans scam which destroyed several businesses.
The SME Alliance's report into the GRG aims to gather "evidence of dishonesty and lack of integrity by RBS executives" which it hopes will allow the Financial Conduct Authority (FCA) to take disciplinary action through a piece of regulation known as the senior managers' regime (SMR).
While the SMR only came into force in 2016 and cannot be retroactively enforced, the SME Alliance expects to have evidence alleging RBS covered up the behaviour at the GRG after it was introduced, and failed to co-operate or notify authorities of behaviours that would breach the regulations.
It also hopes to bring the case into the jurisdiction of the FCA by showing that in the majority of cases, the bank insisted on personal guarantees for small business loans that could categorise them as personal finance transactions.
Commercial lending to SMEs (small and medium-sized enterprises) is still not regulated by the FCA.
The allegations and arguments will be laid out in a report that will be handed to the FCA and made public by year-end.
Ms Turner said: "Our members are extremely frustrated that the regulators are unable to take any action against RBS and its bankers.
"The FCA say it cannot find any way to take action - we aim to help them ensure that the guilty bankers are brought to book."
RBS and the FCA declined to comment.