WASHINGTON (AP) — All five Republicans on the House ethics committee and the panel’s ranking Democrat withdrew from a long-standing investigation of Democratic Rep. Maxine Waters of California on Friday to avoid further questions about their impartiality.

The extraordinary development came more than two years after the panel began examining whether Waters tried to steer money from the 2008 financial bailout to a minority-owned bank while her husband was a shareholder and board member of the institution.

The mass recusal came in one of the committee’s most troubled cases, after past allegations of bias by Republican members forced the panel to hire an outside lawyer last July to investigate the committee and its handling of the Waters case.

The committee’s Republican chairman, Rep. Jo Bonner of Alabama, said the outside attorney, Billy Martin, requested the recusals. But Bonner said the recusals “are not based on any indication of any wrongdoing or inappropriate partisanship by the members.”

Waters, a high-ranking member of the Financial Services Committee, was accused by the panel of trying to use her influence to obtain federal aid for a minority-owned bank where her husband is an investor.

During an investigation that has gone on for more than two years, Waters, one of the longest-serving African-American lawmakers, has consistently denied wrongdoing, saying her efforts were focused on helping a number of minority-owned banks that were in financial trouble.

In addition to the five Republicans on the committee, its senior Democrat, Rep. Linda Sanchez of California, also withdrew from the case — even though she was not a committee member when the allegations of bias surfaced. In fact, all five of the Democrats on the committee in 2010 quit the panel when Congress convened in January last year, saying new members were needed to take a fresh look at the Waters case. However, all five Republicans decided to stay on.

The five Republicans stepping down were Bonner and Reps. Michael McCaul of Texas, K. Michael Conaway of Texas, Charles Dent of Pennsylvania and Gregg Harper of Mississippi. Replacements have already been named to allow the Waters case to continue.

The chairman said Martin advised the committee that, to date:

—He has not discovered any evidence to indicate bias or partiality in the investigation.

—He has not discovered evidence that should cause a mandatory removal of anyone from the case.

—There is no conflict that would require disqualification of any current member or staff of the committee.

The six members, Bonner said, “believe that, out of an abundance of caution and to avoid even an appearance of unfairness, their voluntary recusal will eliminate the possibility of questions being raised as to the partiality or bias of committee members considering this matter.” He said the investigation is continuing “in a fair and unbiased matter.”

Replacement members are Republican Reps. Bob Goodlatte of Virginia, Steven Latourette of Ohio, Mike Simpson of Idaho, Shelley Moore Capito of West Virginia and Tim Griffin of Arkansas and Democratic Rep. John Sarbanes of Maryland.

In August 2010, the committee charged the 11-term congresswoman with three counts of alleged ethics violations. Waters asked for a proceeding that would amount to an ethics trial, but it never took place after internal committee turmoil erupted over the case.

The investigation revolved around whether Waters helped OneUnited Bank obtain federal bailout funds in late 2008. Her husband, Sidney Williams, served as a member of OneUnited’s board of directors from January 2004 until April 2008 and is a shareholder in the bank.

Waters asked the Treasury Department to meet representatives from the National Bankers Association, a trade group representing minority-owned and women-owned banks including OneUnited. The discussion focused on OneUnited, the committee said.

Waters contended that the National Bankers Association requested the meeting and insisted it was held on behalf of the association, not OneUnited. OneUnited eventually received $12 million in bailout money, but federal officials have said Waters was not involved in the decision.

The trial was postponed indefinitely after internal committee memos surfaced that showed the two staff attorneys working on the case were communicating solely with Republican members of the committee. The Democratic chairman at the time, Rep. Zoe Lofgren of California, dismissed the lawyers, angering Republicans who said they did nothing wrong.

When the outside counsel was hired last July, the committee said, “Serious allegations have been made about the committee’s own conduct in this matter by Representative Waters and others. The committee has not taken these allegations lightly. The entire membership of the Committee on Ethics believes that its work must always comport with the highest standards of integrity.”

Copyright 2012 The Associated Press.