The Senate Ethics Committee has uncovered extensive evidence that former Sen. John Ensign (R-NV) and others broke U.S. law by trying to cover up an affair Ensign had with a campaign aide, the wife of one of his top Senate staffers.

The panel has forwarded the evidence of criminal activities to the Department of Justice for further investigation, which it is required to do in any investigation that turns up evidence of criminal wrongdoing, Sens. Barbara Boxer (D-CA), who chairs the ethics panel, and Johnny Isakson (R-GA), said in letters to the DOJ and FEC released Thursday along with a final report from a special prosecutor handling the case.

"The committee voted unanimously to refer Senate findings to the Department of Justice and the Federal Election Commission because we have reason to believe that Sen. Ensign violated laws within their jurisdiction," Boxer said in a rare floor speech addressing the committee's usually private proceedings.

The evidence the committee uncovered, was so egregious, Boxer said, that a special counsel assigned to the case was set to recommend expulsion had Ensign not resigned. The potential criminal actions include aiding and abetting the violation of the one-year post-employment lobbying ban, discrimination on the basis of gender, false statements to the FEC and obstruction of justice, among others.

Noting that Ensign was still holding fast to the claim he had not broken the law when he he announced his resignation, Boxer said she wanted to "go on record as chairman of the Ethics Committee to say how strongly I disagree with that statement."

"The committee believes that that every senator should read this report very carefully because it is a cautionary tale, because it says our actions have consequences for our families, for our staff...," she said Thursday on the Senate floor. "We must ensure that every action that we take is above the law. And it my personal view it shows something else. When you are in a position of trust and power, don't abuse it, don't misuse it because people can get hurt—very, very hurt."

"It's a sad chapter for the Senate but a sadder chapter for the lives it destroyed," she added.

Boxer and Isakson said the committee thoroughly examined the case against Ensign, deposing more than 72 witnesses and scrutinizing more than half a million pages of documents.

The committee "did not act on what it thought, on an opinion or a whim," Isakson said.

The conclusion of the case is two years in the making. In 2009 Ensign admitted to having an affair with a former campaign aide, Cynthia Hampton, and then helping her husband, also a top aide, establish a brief lobbying career.

Formal accusations and charges have focused on the great lengths — and potentially illegal steps — Ensign took to keep the affair quiet, including having his parents (wealthy Las Vegas casino owners) pay the Hamptons $96,000 in hush money.

Ensign was also accused of knowingly helping Doug Hampton violate the one-year lobbying ban by helping him set up a short-lived job on K Street.

In March federal prosecutors charged Doug Hampton with seven counts of violating conflict-of-interest laws. In December Ensign said the Justice Department had told him he was no longer a target in its probe, but shortly after the Ethics Committee's hiring of a special counsel to continue its investigation, Ensign said he would retire instead of seeking reelection.

The Federal Election Commission said the $96,000 payments did not violate campaign-finance law because they were paid in installments to the Hamptons and their children in amounts allowed under U.S. tax law.

Still insisting he did nothing wrong in announcing his resignation in April, Ensign said he decided it was time to go after the Ethics Committee named a special prosecutor to continue looking into the matter, even though he believed the Justice Department had dropped its case and the FEC has dismissed the accusations against him.

You can read the full Ethics report here.

Republished with permission from TalkingPointsMemo.com. Authored by Susan Crabtree. Additional reporting by Ryan J. Reilly. Photo via AP. TPM provides breaking news, investigative reporting and smart analysis of politics.