The enlisting of Beth Wilkinson - a partner at Paul, Weiss, Rifkind, Wharton & Garrison LLP and former Justice Department prosecutor - is thought to be a big boost should the regulator choose to bring a case against Google.
A Google spokesperson declined to comment on the development.
Wilkinson is expected to be closely involved in the FTC's ongoing determination on whether to bring a case against the US search giant. She would also likely be involved in the litigation, should it materialise.
In an interview with the Wall Street Journal, FTC commissioner J. Thomas Rosch said that Wilkinson would mentor the regulator's staff, and "carry out the duties of a trial lawyer".
Rosch stressed that the agency had not yet reached a conclusion in the Google probe, but he tellingly added: "Obviously we would not bring her in if she were going to be completely idle."
Last year, the commission launched an investigation into whether searches on Google unfairly direct web users to the company's own services, at the expense of rivals.
The European Union is also investigating Google's web search practices.
Wilkinson, who became known as the lead prosecutor in the case against Oklahoma City bomber Timothy McVeigh, has entered a one-year, part-time contract with the FTC, starting next Monday.
Richard Feinstein, head of the FTC's competition bureau, said: "We are delighted to have someone of her calibre helping us on such an important matter for the Commission."
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