The banker who branded Goldman Sachs a "toxic and destructive" firm focused on milking clients is depicted in an internal Goldman report as an underperformer who was frustrated with his pay and prospects.
Goldman released details to media from its internal probe into Greg Smith, a former manager in the London office who caused a stir when he announced his resignation in a tirade published in the New York Times.
Smith wrote on March 14 that the Wall Street giant, which paid huge penalties for double-dealing with investors in mortgage securities during the financial crisis, had dumped its old culture of honestly helping its customers make money.
Goldman customers are called "muppets" by top executives and staff talk about "ripping their clients off", he wrote.
But according to a Goldman source familiar with the internal review, there was no evidence to back his claims.
Instead, Smith was among the bank's poorest-performing employees and was angered over not getting promoted.
"Between 2007 and 2012 his performance scores generally declined," the source said.
Smith earned about $US500,000 ($A484,660) per year, and told a superior in December 2011 that he was frustrated with his progress and had hoped to earn $US1 million a year and be promoted to managing director level.
When he got his compensation notice in January 2012, however, he was disappointed and had "an excessive reaction", said the source.
The report found that in a search of millions of emails Goldman could find only one instance where a client was referred to as a "muppet".
The report also said that Smith never expressed concerns about a change in Goldman's culture until immediately before his resignation.
Goldman released the details of the internal probe days before Smith's book, Why I Left Goldman Sachs, is published on Monday.
Citing an advance copy of the book, Politico.com said Smith described lavish parties and free-spending holidays by the well-paid senior officials of Goldman.
"Getting smashed with your clients was a regular occurrence," Smith wrote.