The allegations of insider trading centre on Matthew Devlin, the former Lehman Brothers broker, who is alleged to have passed on information secretly gleaned from his wife, a public relations executive, to a trading ring that made almost $4.8 million in profits.

The ripples stretch far and wide. According to the Securities and Exchange Commission (SEC), the inner circle comprises Mr Devlin and at least four of his clients and friends: he tipped them off with details of deals involving clients of his wife, Nina.

Mrs Devlin is not implicated in the charges. A lawyer for Mrs Devlin said: "She was completely unaware that confidential information about her job was being used as the basis for securities trading."

The clients that Mr Devlin passed on information about included Anheuser-Busch, the American brewer which, at the time, was the subject of a multi-billion dollar takeover approach from InBev, the Belgian-Brazilian brewer.

The members of that inner circle, in turn, passed on Mr Devlin's tips to clients, friends and relations of their own. According to the charges against Mr Devlin brought by the SEC, a further 11 people were involved in Mr Devlin's activities.

Unravelling the fraud

Matthew Devlin, 35, of Lehman Brothers now at Barclays Wealth. He has since been suspended from his job.

— Married Nina Devlin, an executive at the international PR firm Brunswick, in 2003. Mrs Devlin was referred to by her husband as "the golden goose".

— Mr Devlin informed at least four of his clients and friends about thirteen impending corporate transactions involving clients of his wife.

1. Jamil Bouchareb

— Friend and client of Mr Devlin's at Lehman. Aged 27. Self-employed; has described himself as "syndicate trader" and "restaurateur".

— Alleged to have traded on about 12 of the deals. He denies the charges.

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