Last week, JPMorgan Chase, an American bank, agreed to pay $410 million (€309million) to the US energy regulator to settle allegations that it had manipulated power markets in California. The settlement terms took a familiar form: the bank neither admitted nor denied wrongdoing. In which case, why did it make the payment? In March, SAC Capital - a US hedge fund accused of insider trading - paid $614 million to resolve matters in a civil case, again without admitting liability. But last month SAC Capital faced criminal charges of insider trading, in a major escalation of the prosecution's case against the company. And last week, America's financial regulator won a notable court victory when a jury found a former Goldman Sachs banker had misled investors in a $1 billion mortgage securities fraud.

However, many of the settlements US authorities have reached with errant financial institutions have involved a form of plea bargaining - via deferred prosecution agreements (DPAs). There, a company admits wrongdoing, pays a fine and prosecution is suspended. In the US, the authorities have long favoured this approach. They remain fearful a criminal prosecution will fail, given some past high profile defeats in court, but feel they need to take some action, rather than do nothing. Justice, to be done, must be seen to be done. And where those suspected of committing financial crimes can reach settlements in private and in secret, rather than publicly and in open court, justice is not well- served.

In Britain, deferred prosecution agreements are likely to be introduced next year, but with the court exercising close judicial scrutiny to ensure they are taken in the public interest. Transparency International Ireland has pressed for the introduction of DPAs here. And in 2010 the director of corporate enforcement also favoured their adoption. However, their increased use in the US in recent years has raised questions about their effectiveness and fairness, both in administering justice and in tackling white-collar crime.