US money manager Sir Allen Stanford has refused to co-operate with the US government’s investigation into an alleged $8 billion fraud at the companies that bear his name as it emerged that Stanford executives had expressed concerns over the accuracy of the group’s financial statements weeks before US regulators made their move, the Financial Times reported.

In a court filing released yesterday, Sir Allen invoked the fifth amendment and said he would decline to testify or produce any documents related to the civil complaint by the Securities and Exchange Commission.

The case, while not as large as the massive alleged fraud perpetrated by US money manager Bernard Madoff, has shaken investor confidence in financial markets and the institutions that handle clients’ money.

Sir Allen’s attorney, Charles Meadows, maintains that the SEC’s claims against his client are false.

In pleading the fifth amendment, Sir Allen joined James Davis, his college roommate and chief financial officer of the Stanford group, who last month refused to co-operate with the investigations.

The SEC went public with its allegations on 17 February. But the documents show that on 13 February, Lena Stinson, Stanford’s chief compliance officer, threatened to report her concerns to the

US watchdog unless the company immediately stopped accepting deposits and revised its financial statements. Ms Stinson highlighted “issues” regarding the accuracy of SIB’s financial statements in particular.

Meanwhile, while
US prosecutors have charged Bernard Madoff with two counts of international money laundering, a UK-led probe into his

London operations, Madoff Securities International, remains at an early stage, according to people close to the investigation.

The Serious Fraud Office, which handles
Britain’s most complex financial cases and has been investigating the company since December, is still trying to unravel the tangled flow of Madoff-linked money between the
UK, Europe and the

US.