Virgin Money boss Jayne-Anne Gadhia has blamed an "alpha male" culture at Royal Bank of Scotland and Fred Goodwin's obsessive drive for growth for contributing to the lender's near collapse during the financial crisis.
Mrs Gadhia - who served as managing director of the RBS mortgage division and then its consumer finance division between 2001 and 2007 - said she enjoyed her time at the bank but noticed a cultural shift following its takeover of NatWest in 2000.
"It was such a brilliant deal to have done. It made RBS this great bank in Scotland, one of the biggest banks certainly in the country and probably one of the biggest banks in the world and as a result I think the management team - Fred Goodwin in particular - were feted for that success," she told the BBC's Desert Island Discs programme.
"What that did, I think, was to create a drive for more and more of that growth and that success and result, and in the end, that overfocus on the output at all times meant that the senior management there lost control, both of the business itself and the culture that underpinned it."
In April 2008, RBS announced a rights issue, asking existing shareholders to inject £12 billion into the firm to strengthen its reserves after it splurged £49 billion to acquire Dutch bank ABN Amro.
The deal proved toxic and, just months later, the value of RBS shares plunged 90%, prompting its £45.5 billion Government bailout. RBS is still 73% owned by the taxpayer.
"I think that in a very alpha male culture - and certainly we saw a bit of it, a lot of it maybe, at RBS - it was an attitude of win-lose. You know, 'I am going to win, I am going to succeed at all costs' and I think that has been very damaging."
Disgraced former boss Mr Goodwin - who served as chief executive between 2001 and 2008 - has avoided criminal charges related to the bank's near collapse and recently escaped a humiliating High Court appearance after shareholders settled a claim against the lender in June.
RBS also recently reached a £4.2 billion US settlement over claims it mis-sold toxic mortgage bonds in the run-up to the crash.
Mrs Gadhia said she was personally approached about getting RBS involved in subprime mortgage securities - one of the complex financial instruments blamed for the banking crisis.
"It wasn't Fred Goodwin at all that asked me to do this, but one of his team asked me why we were not securitising subprime mortgages," she explained.
"We scratched our heads and said how does that work then? But not because we could see the train coming down the track, but because we thought all these really clever people really knew what they were talking about and we didn't.
"And it made me think: if I don't understand anything, I'm not going to do it."
Mrs Gadhia left RBS alongside a raft of former Virgin Direct employees by 2007, taking up an offer by Richard Branson to join Virgin Money.
She says banking has been "transformed" since the crisis, not least on the back of a regulatory crackdown.
"But at the end of the day it's people that will make the difference and having good people that do the right thing for the right reasons."
She added: "Being driven by the profit motive purely is never, ever going to result in the best form of banking."