The House Ethics Committee has voted unanimously to hire Billy Martin as an outside Counsel to finish the investigation of allegations Rep. Maxine Waters, D-Calif., used her office to improperly funnel Troubled Asset Relief Program (TARP) funds.

The committee says the decision "reflects the high priority of this unique matter and we need to resolve it with the utmost care, diligence and integrity."

On Tuesday, Fox News obtained a formal letter written by attorneys representing Waters and addressed to the House Ethics Committee. It formally asked its members to drop its probe into the conduct of the California Democrat.

Waters' attorneys Stan Brand and Andrew Herman wrote the letter to House Ethics Committee Chairman Jo Bonner, R-Ala., and ranking member Linda Sanchez, D-Calif.

In the letter, Waters' counsel argues that a variety of leaks, illegal transmission of material and "the intentional and malicious misleading of members and staff relating to the investigation" should compel the committee to drop the investigation.

"This misconduct is of such a fundamentally improper level that it cannot be cured by reliance on any other device, including employment of an outside counsel," they write. "Simply put, given the foregoing history, this Committee can never conduct an impartial and unbiased inquiry into this matter."

Last year, Waters asked the committee to drop its investigation.

The panel accused Waters of improperly using her position as a lawmaker to help secure TARP funds for a bank in which she owned stock and her husband sat on the board of directors.