Billionaire arrested in insider trading case

A billionaire hedge fund manager was among six people arrested in a hedge fund insider trading case that US prosecutors say reaped $20m in illegal profits.

Raj Rajaratnam, a partner in Galleon, a hedge fund with up to $7bn in assets under management, was accused of conspiring with others to cause trades based on insider information about three publicly traded companies, Polycom, Hilton Hotels and Google.