Royal Bank of Scotland has been accused of fraud and forgery by an ex-employee and former customers, according to a BBC report.
Mark Wright, who worked at NatWest and remained there after it was taken over by RBS, said the employees who forged the complaints were from the bank's Group Compliance Unit.
Wright's five customers later gave statements contradicting the fake complaints, and the accused staff left the bank.
According to Wright, RBS failed to properly investigate the complaints, and did not afford him whistle-blower status.
RBS could not be reached for comment this morning, but a spokesperson for the bank told the BBC that Wright's concerns had been thoroughly investigated and responded to, and denied that any systematic document tampering had gone on at the bank.
Meanwhile, the BBC also reported a number of former RBS customers have alleged that the bank forged documents relating to transactions and loan agreements.
The bank also denied these allegations.
It was revealed today that RBS is one of the five UK banks that have run up a £100bn bill for bad loans and legal costs in the last five years.