News of the probe by the industry regulator follows an internal enquiry into the traderâs actions by his employer.
Mr Rambourg received a suspension from his post as a fund manager after he was found to have directed specific trades to certain investors.
The trader returned to work as an analyst following the completion of the investigation while the firm announced it wanted to reinstate him to his previous role as quickly as possible.
In a statement, Gartmore said: âThe FSA has now confirmed that it is to commence an investigation into the conduct of Guillaume Rambourg to determine whether he has met the standards required of an FSA approved person.â
The investigation is focused wholly on Mr Rambourg and not the firm or any other employee, the company explained.
According to Gartmore, a new licence for Mr Rambourg to work again as a fund manager would be applied for âsubject to a satisfactory outcome of the FSA investigation".
By Jim Ottewill