The boss of one of the UK's biggest banks has been named in Parliament as being responsible for RBS's scandal-hit Global Restructuring Group (GRG).
Nathan Bostock, who is now head of Santander UK, was named by the Liberal Democrat leader Sir Vince Cable.
Mr Bostock was one of those responsible for GRG when it engaged in an intentional strategy that resulted in mistreatment of business customers, Sir Vince said.
Santander declined to comment.
Mr Bostock's name came up in a wide-ranging debate where MPs across all parties attacked regulators and senior bankers for failing to offer victims adequate redress.
Between 2008 and 2013 Royal Bank of Scotland put 16,000 business customers into its GRG division, telling many it was there to help turn their fortunes around.
However, an internal inquiry for the Financial Conduct Authority found in 2016 that the bank had instead systematically put its interests ahead of its customers.
After the report was leaked to the BBC last summer, the FCA's chief executive Andrew Bailey refused MPs' demands to publish it in full, instead opting for a summary which omitted key phrases and names.
In a backbench debate on GRG on Thursday, Sir Vince Cable said the full report mentioned an "incriminating phrase": "Management knew or should have known that this [was] an intended, co-ordinated strategy, the mistreatment of business customers was a result of that, and that the head of GRG responsible for that policy, Mr Nathan Bostock, is now chief executive of Santander."
MPs attacked GRG for treatment which had resulted in customers losing not just their business but often their homes, their marriages or their health.
Labour MP Clive Lewis said: "The cost of this is immeasurable, but we believe it to be in the tens of billions. So let's be clear here. This is the potential size of the injustice that has taken place in our country. If it is this big, it may be the largest theft anywhere, ever."
In one extract of the unpublished report, it publishes an internal memo of tips for dealing with business customers with language such as: "Rope. Sometimes you need to let customers hang themselves."
Conservative MP and Treasury select committee chairwoman Nicky Morgan said the memo "lifts the lid on a culture at RBS".
"When I hear constituents and others say that they will never trust a bank again, they will never ask a bank again for money, then this should be a chilling moment for all banks involved in lending and working with SMEs."
MPs in the all-party parliamentary group on fair business banking now want a new system of tribunals to allow better access to justice for small business owners - for whom suing the bank is either impractical or unaffordable.