LONDON The Financial Conduct Authority (FCA) said three men and a woman have been arrested on Wednesday and held in custody as part of an investigation into insider dealing and market abuse.
"The arrests are not linked to any other ongoing insider dealing investigation," the UK markets watchdog said in a statement.
The FCA, with the assistance of the Metropolitan Police, used search warrants in west London and arrested three men aged 29, 51 and 56, and a woman aged 25.
The four individuals did not work for major financial organisations and were not senior employees, who need regulatory approval before being handed important positions, a source familiar with the investigation said.
(Reporting by Huw Jones and Kirstin Ridley)