The bank's traders created a number of financial deals that allowed Greece to raise money to cut its budget deficit immediately, in return for repayments over time. In one deal, Goldman channelled $1bn of funding to the Greek government in 2002 in a transaction called a cross-currency swap. On the other side of the deal, working in the National Bank of Greece, was Petros Christodoulou, who had begun his career at Goldman, and who has been promoted now to head the office managing government Greek debt. Lucas Papademos, now installed as Prime Minister in Greece's unity government, was a technocrat running the Central Bank of Greece at the time.

Barroso, who was president of the European commission for 10 years until 2014, is becoming chairman of Goldman Sachs International – the bank’s UK and European operations – and will also be an adviser. His pay has not been disclosed.

Corrupt bankers represent a threat not only to those they directly rip off but also potentially the entire global financial system, the Governor of the Bank of England has warned.

In his capacity as chair of the Financial Stability Board (FSB) – a global forum for national regulators, financial ministries and central banks – Mr Carney has written an open letter to the G20, which meets in China this weekend.

“The incidence of financial sector misconduct has risen to a level that has the potential to create systemic risks by undermining trust in both financial institutions and markets,” he says.

Dubbed the biggest rogue trader in British history, Kweku Adoboli ran up $2.3bn of losses for the Swiss bank UBS. He has spent four years in prison for fraud and now faces possible deportation from Britain back to Ghana. He maintains he was not motivated by greed but that the system put unbearable pressures on him to make big returns. He warns that the culture of the banking industry has not changed very much which means it could easily happen again.

British workers are among the most jealous in the world, with one-third believing colleagues who receive bonuses do not deserve the additional payouts.

Just over one-third of finance professionals believe bonuses given to top earners are unjustified, according to a study by the Chartered Institute of Management Accountants (CIMA).

Only workers in the United Arab Emirates are more hostile to bonuses, out of the 14 countries examined in the report.

The study also found that 62pc of finance workers believe unjustified bonuses cause resentment in the office, souring the atmosphere at work.

Bonuses are most disliked if they are perceived to boost short-term thinking among executives, and when critics believe the awards encourage workers to focus on one small area of their job rather than the overall picture.

“Perceptions of ‘unjustified’ bonuses, whether stemming from ineffective incentive designs or not, can trigger resentment and undermine employee engagement and motivation. This hurts performance, exacerbates myopia and corrodes culture,” said professor of accounting and financial management Wim A Van der Stede.

“Designing effective incentive systems is hard, yet incentives that may be fair may not look fair – a challenge that touches on the issue of transparency as well as the question of both how and how much to incentivise.”

CIMA suggests that bonuses should be more explicitly linked to long-term performance and the business’s ultimate goals, rather than short-term metrics such as revenue.

For years, bank officials denied any intent to transform Goldman Sachs into the sort of bank that dealt with Main Street consumers. They argued Goldman’s bank would only cater to the wealthy individuals and corporations that had long been its client base.

But management’s thinking has evolved as regulators have pushed the industry to get back to the basics of banking, said the sources, who were not authorized to discuss strategy publicly. For Goldman, deposits also represent a more stable and stickier type of funding than other types of short-term debt it has relied on historically.