Bernard Madoff is serving 150 years for fraud.
No prosecutions will take place in Britain in connection with the multibillion-dollar fraud carried out by Bernard Madoff.
Investigators from the Serious Fraud Office have been investigating Madoff Securities International, the British arm of his operations.
But it said no further action would be taken against the firm or its directors owing to insufficient evidence.
Madoff, aged 71, is serving 150 years for a $65bn (£41bn) fraud.
A Serious Fraud Office spokesman said inquiries into "wider aspects" of the fraud continued, as did work with overseas agencies, which is said "may give rise to offending in the UK".
But the spokesman added: "Following a thorough review of all the available evidence, it has decided to take no action against either the company or its directors, there being insufficient evidence to provide a realistic prospect of conviction."
Bernard Madoff admitted defrauding thousands of investors through a Ponzi scheme, which pays out using new investors' money rather than from any profits.
He said the scheme had been running since the early 1990s.
It unravelled when Madoff's investors, hit by the economic downturn, tried to withdraw about $7bn, but he could not produce the money.