Five individuals have been arrested and are being held in custody to be questioned in connection with an investigation into insider dealing and market abuse.
The FSA and police executed four search warrants this morning in the City of London, Lincolnshire, Leicestershire and North Yorkshire.
Two men aged 37 and 62 and three women aged 39, 51 and 63 have been arrested.
None of the individuals have been charged at this stage, and the arrests are not linked to any other ongoing insider dealing investigation.
The FSA is currently prosecuting six other individuals for insider dealing. It has secured 21 insider dealing convictions since March 2009.
Insider dealing is punishable by either a fine or a prison sentence of up to seven years.