Search warrants were executed at a number of addresses in Greater London
The Financial Services Authority (FSA said it arrested two people, including a senior corporate finance adviser, following a probe into insider dealing.
Search warrants were also executed by the FSA at a number of addresses in Greater London as part of the investigation.
The operation involved 25 FSA staff, assisted by 11 officers from the City of London Police, and is part of the FSA’s work to tackle market abuse.