An analyst employed by hedge fund firm Man Group is under investigation by the Financial Services Authority for possible insider dealing, the company confirmed on Thursday.
The unnamed employee, who worked in Man's GLG unit, was one of three men arrested by the Metropolitan Police on Wednesday as part of a probe by the regulator into alleged market abuse.
"Man has been informed by the FSA that the investigation concerns the individual's actions as a private individual and not as an employee of Man or GLG," a spokeswoman said in an emailed statement.
"Neither Man nor GLG is the subject of the investigation and we have co-operated fully with the FSA's enquiries."
The employee has been suspended by Man Group, which reports annual results on Thursday.
(Reporting by Sinead Cruise, editing by Chris Vellacott)