Five people, including two former directors and one former trader at the derivatives brokerage Blue Index, have been charged with insider dealing by the Financial Services Authority, the market watchdog.
Blue Index's co-owners James Paul Sanders and James Swallow, and senior trader Christopher Hossain were among those charged with offences alleged to have taken place between October 2006 and February 2008.
Mr Sanders's wife, Miranda Sanders, and a former Blue Index employee Adam Buck were also charged. The five suspects, who were arrested in May last year, have been bailed to appear at the City of Westminster Magistrates Court next month.
The group faces 17 counts of insider dealing in what is the latest in a series of FSA crackdowns. The watchdog is in the process of prosecuting 11 other people for insider dealing.