The ethics investigators found that Mr. Buchanan, one of the richest members of Congress, tried to get his ex-partner to sign a legal affidavit that he knew to be false before he would agree to pay the partner a $2.9 million settlement in a business dispute. The affidavit wrongly asserted that Mr. Buchanan knew nothing of illegal contributions made to his campaign in 2006, the investigation by the Office of Congressional Ethics found. The board overseeing the Office of Congressional Ethics, which investigates allegations of wrongdoing by House members, found in the newly released report that there was “substantial reason to believe” that Mr. Buchanan violated federal law and Congressional rules by attempting to influence the testimony of a witness in a federal inquiry. In releasing the report of its investigative arm, the House ethics committee’s Republican and Democratic leaders said the committee would continue to examine the allegations against Mr. Buchanan — just months after the committee announced it was examining a separate set of allegations involving his incomplete financial disclosure statements. Mr. Buchanan refused to cooperate in the ethics office’s investigation, but his lawyers said in a letter that it was “fundamentally flawed” and relied on the testimony of unreliable witnesses in concluding that the congressman tried to buy the testimony. The lawyers said that the investigators’ conclusions were “nothing short of bizarre.” Max Goodman, a spokesman for Mr. Buchanan’s congressional office, called the report “a disgrace” in a separate statement and said he was confident the ethics committee would ultimately dismiss what he called “old, recycled accusations.” He cited an earlier investigation by the Federal Election Commission, which dismissed the case against Mr. Buchanan but only after investigators there initially found that he knowingly accepted illegal campaign contributions. The release of the investigation and the ethics committee’s decision to continue examining the allegations escalate the political pressure on Mr. Buchanan and House Republicans. Mr. Buchanan serves as a fund-raising leader for House candidates nationwide at the National Republican Congressional Committee. As Mr. Buchanan has made recent fund-raising appearances with Republican leaders like Speaker John A. Boehner, Democrats have sought to seize on the allegations against him in attacking him and the party. The ethics committee has been the battleground for numerous political clashes in the last year — most of them involving Democrats. The leaders of the committee — Jo Bonner, Republican of Alabama, and Linda T. Sánchez, Democrat of California — could have decided to drop the investigation into Mr. Buchanan, or they could have moved forward with a full investigation and possible disciplinary action against him. Instead, they took a middle ground that the committee has used in a number of recent cases by simply extending the inquiry. Mr. Buchanan is also facing ongoing investigations by the F.B.I. and the I.R.S. involving allegations of financial wrongdoing in his private business dealings and his campaign finances. The congressman built his fortune in part on a string of auto dealerships he owns in Florida and elsewhere. The evidence cited in Wednesday’s report centers on his relationship with Sam Kazran, his former partner in a Hyundai dealership in North Jacksonville, Fla. The two men had a bitter falling out over a number of business disputes and were negotiating a financial settlement in the fall of 2008 that would have paid Mr. Kazran $2.9 million. But Mr. Buchanan and his lawyer made the settlement contingent on Mr. Kazran’s signing a seven-page affidavit that said the congressman did not know of and was not involved in the improper reimbursement of contributions to his campaign made in the name of executives and employees at the Hyundai dealership. At the time, the Federal Election Commission was investigating allegations that the contributions were illegally laundered. Mr. Kazran said he refused to sign the affidavit because it was not true. He asserted that, in fact, Mr. Buchanan had personally directed the dealership’s reimbursement of contributions to his campaign totaling about $100,000. Mr. Kazran said he began personally asking some employees for contributions in late 2005 and then reimbursed them from corporate funds at Mr. Buchanan’s explicit direction. The ethics office found that e-mails and voice mails between Mr. Kazran, Mr. Buchanan, and a top executive at Mr. Buchanan’s company indicated that the congressman knew of the laundered contributions — and knew that the affidavit exonerating him was false — at the time he asked his ex-partner to sign it. The ethics investigators said Mr. Buchanan personally pressured his ex-partner to sign the document. In one voice mail, Mr. Buchanan warned his ex-partner not to make good on threats to sue him, saying that “you got more liability than you know if you start telling people that you reimbursed people, because technically you have the liability,” according to the 184-page report. The ethics office did not directly address the question of whether Mr. Buchanan had improperly taken part in the illegal reimbursement of contributions to his campaign. Those contributions came before the House voted to create the ethics office in March 2008, and so were considered outside its scope. But the efforts to get Mr. Kazran to sign the affidavit effectively exonerating Mr. Buchanan of any wrongdoing came in October 2008 and thus fell within the investigators’ scope.
