Conceicao, who formerly headed up the Financial Service Authority’s (FSA’s) wholesale enforcement division, has been handed the task of sifting through thousands of pages of documents, which could link Rambourg to a number of “directed trades”.
The investigation into Rambourg, who was suspended last week from Gartmore, centers on unauthorized trades rather than insider dealing.
Conceicao, who joined Clifford Chance three years ago, has led investigations into FTSE 100 companies at the financial regulator, including handing oil giant Shell a £17m fine for committing market abuse and breaching listing rules.
He would not comment on the investigation or any other members of the firm who are involved.
The news comes as it has emerged that Gartmore is currently under investigation by the US Securities and Exchange Commission (SEC).
The SEC launched the investigation of the fund in December just months after the company launched an initial public offering.
Gartmore management has insisted that the SEC investigation is not new and is not linked to the European desk where Rambourg worked.
Chief executive Jeff Meyer said that no clients suffered any impact as a result of an inadvertent breach of SEC regulations, which he said Gartmore reported to the authorities as part of its “zero tolerance approach.”
Meanwhile, Rambourg was fined €300,000 (£264,692) by Italian regulator Consob last month for breach of regulatory rules.
Gartmore saw shares fall dramatically upon news it had suspended Rambourg, although they stabilised by the end of the week.