Documents published online for the first time Thursday indicate that the FBI opened an inquiry into New Jersey Democratic Sen. Bob Menendez on August 1, 2012, focusing on repeated trips he took to the Dominican Republic with longtime campaign contributor and Miami eye doctor Salomon Melgen. TheDC reported in November that Menendez purchased the service of prostitutes in that Caribbean nation at a series of alcohol-fueled sex parties.

The documents, which The Daily Caller had obtained hours earlier from an anonymous source, also indicate that Carrie Levine, research director at Citizens for Responsibility and Ethics in Washington (CREW), was alerted on April 9, 2012 to Menendez’s habit of paying for sex while outside the United States. (RELATED: Read the tipster’s dossier on Sen. Menendez)

ABC News senior investigative producer Rhonda Schwartz was aware as early as May 2, 2012, the documents show, when Levine wrote a source in the Dominican Republic to say that she had “shared your allegations, but not your identities, with a respected, trusted journalist with whom we have worked on other stories.”

In another email two days later, Levine identified that journalist as one who “works for ABC News.” By May 16, Schwartz was emailing Levine’s original source with questions.

Information made available to Schwartz and Levine at that time included allegations that some of Menendez’s prostitutes were as young as 16. The source also alleged that Sen. Menendez was taking “non-authorized trips” to the Dominican Republic, suggesting that he may have been evading Senate Ethics committee rules covering disclosures when third parties pay for a senator’s travel. (RELATED: NRSC says Menendez may have broken Senate ethics rules, federal campaign finance laws)

Those rules require senators to secure approval from the committee before allowing a private person or company to provide transportation or lodging related to official business. But the Senate’s “gift rule database,” available online, contains nothing related to a Menendez visit to the Dominican Republic.

The rules also allow senators to accept free lodging or travel as gifts from friends. Those transactions must also be documented on an annual financial disclosure report, and approved in advance by the Senate Ethics committee if the value is more than $335. Menendez’s disclosures since the mid-1990s, when he was a member of the House of Representatives, include no mention of such gifts.

On Sept. 11, 2012, the documents indicate, the same source who provided information to Levine and Schwartz also sent an FBI Special Agent in Miami what he described as “the testimony of one of the girls.”

“I have in my possession the original written in her own hand,” the source wrote. “She’s 19 now, but took part in private parties with Senator Menendez being only 16.”

That testimony-style interview was published online along with the other Menendez-related documents on Thursday.

With an interviewer asking her to identify a photograph of Menendez, the unnamed woman replies, “I don’t need to look again. I’m quite sure this is Bob Menendez, the friend of Salomon Melgen I had sexual relations with. I had sexual relations with him several times and I can’t forget his face.”

“I actually met him as Bob,” she says in the transcript. “Then I knew who he was, that he’s a Senator in the United States and that his name is Bob Menendez.”

Asked how often she had sex with the senator, she replies, “In 2009 I saw Bob three times at least. The first one in February, and then in May and June. I recall his visit in June so well because that month was my 17th birthday. Then we met twice one in May 2010 and then in December 2011. … I was underage when I met him. But I can’t say for sure whether he knew it or not.”

She is identified in the transcript as “young participant #2.”

The age of consent in the Dominican Republic is 18. The PROTECT Act, a U.S. law passed in 2003, made it a federal crime for Americans to engage in sex for money with anyone under 18, even in countries where the age of consent is lower.

CREW executive director Melanie Sloan told TheDC on Thursday evening that her organization shared the allegations it received with federal law enforcement.

“On July 17, 2012, CREW sent letters to the Department of Justice and the FBI requesting an investigation into this matter,” Sloan said in an email. She said one letter was addressed to “[t]he Director of the Washington Field Office.”

A message left for that office’s Acting Assistant Director in Charge, Debra Evans Smith, was not returned.

But CREW has not mentioned Sen. Menendez on its website or in press releases since July 2011, and the group has not identified the New Jersey Democrat as a lawmaker with ethical shortcomings.

CREW publishes an “Under Investigation” report which it says is “a list of Congress members likely under investigation by the Department of Justice, the Federal Bureau of Investigation, the House Ethics Committee, the Senate Select Committee on Ethics, the Office of Congressional Ethics, and in some cases, the Federal Election Commission.”

No senators’ names appear in the report, last updated January 8, 2013. Spokesman Dave Merchant did not respond when asked why CREW did not publicly report the allegations against Menendez in 2012, seven months before Menendez won re-election.

The 58-page dossier on Menendez includes several emails to and from Schwartz at ABC. In one, she wrote to the Dominican Republic source on June 22, 2012 saying that the Menendez story was “a high priority and I’m working on it at my end.” ABC, however, never produced a news report on Menendez’s Dominican escapades during the 2012 election year.

“I’m not going to say anything,” Schwartz told TheDC when reached via phone Thursday. “I’m not confirming anything.”

Schwartz referred questions to ABC News spokesman Jeffrey Schneider, who did not respond to an email seeking comment.

TheDC’s Nov. 1 exposé included videotaped interviews with two women who said through a translator that Menendez paid them for sex at an elite Dominican resort. An attorney representing both women told TheDC that they were both of legal age. Both women said they were promised $500 to sleep with Sen. Menendez, but that they were paid only $100 apiece. (RELATED VIDEO — Women: Sen. Bob Menendez paid us for sex in the Dominican Republic)

Prostitution is legal in the Dominican Republic, but ethics rules prohibit U.S. government officials from engaging in behavior that is illegal in the U.S. since it could open them up to blackmail, compromising their ability to serve in government.

Eleven U.S. Secret Service agents became embroiled in a prostitution scandal in the South American nation of Colombia in early April 2012. Government officials at the time cited exposure to blackmail as one reason the Department of Homeland Security would not tolerate Secret Service agents who paid for sex while on assignment overseas.

That scandal broke within days of when a person using the name “Peter Williams” first contacted CREW about Sen. Menendez. He was an American citizen, he said, with both direct and second-hand knowledge of what Menendez and Melgen were doing — and with whom.

Melgen has donated at least $14,700 directly to Menendez’s various political campaigns, according to Federal Election Commission data collected by the Center for Responsive Politics. The Washington Free Beacon reported on Nov. 1 that Melgen “has contributed at least $700,000 to Majority PAC, a Super PAC dedicated to Democrat candidates for Senate and founded by a former aide to Sen. Harry Reid.”

He also appears to have supplemented those donations by allowing Menendez to travel, free of charge, on his private jet during numerous trips between the U.S. and the Dominican Republic.

The online documents published Thursday on a makeshift WordPress blog include texts of emails, screen-capture images of emails displayed on a Yahoo! account, names of Menendez’s purported prostitutes, and three locations where his pay-for-play trysts are supposed to have taken place.

One, the luxurious Casa de Campo resort, is adjacent to a private airfield Melgen used at least eight times in 2012, according to flight records for his Canadair CL-600 Challenger aircraft that TheDC obtained through FlightAware by tracking the tail number of the aircraft. One of those trips occurred during Easter weekend, when the women interviewed for TheDC’s Nov. 1 story both said they were paid to have sex with Menendez.

Another location is described in the documents as a “private yacht docked at Casa de Campo’s Marina.” (RELATED: Dominican government official says Menendez a frequent guest at “sex, hookers and drinking” parties)

A spokeswoman for Sen. Menendez did not reply to emails and phone messages seeking comment about how many times has he visited the Dominican Republic since taking office; whether he has ever paid for the services of underage prostitutes; whether his use of Melgen’s private jet was related to his campaign or to his official Senate duties; whether his campaign reported travel perks and other in-kind gifts from Melgen in Federal Election Commission reports; whether he is aware of an FBI investigation into his activities; and whether the Senate Ethics committee has contacted him about his trips to the Dominican Republic.

The Dominican source of the documents that are the subject of this article emailed them to TheDC from an Internet address in Mexico. It is unclear whether this is the same person who first tipped off CREW’s Levine about Sen. Menendez, and appears to have communicated later with Schwartz at ABC News, and with the FBI.

The tipster attempted to lodge a complaint with the Senate Ethics committee in the same April 9, 2012 email he sent Levine, but he misspelled the name of the committee’s deputy staff director, Annette Gillis, in her email address. The email did reach Levine, but there is no evidence the committee was informed. Committee staff director John Sassman would not speak on the record when TheDC reached him Thursday evening.

Multiple FBI sources also declined to confirm on the record that Sen. Menendez is under investigation, including Miami-based Special Agents Regino Chavez and Michael Leverock.

“The FBI has no comment … I have nothing further to add,” said Leverock, who coordinates media for the FBI’s Miami Field Office.

Chavez is the agent who appears to have communicated repeatedly with the “Peter Williams” source, whose emails form the bulk of the dossier that went online Thursday.

Another FBI source, speaking on background, would not deny the report — telling TheDC only that the FBI typically would not publicly confirm an investigation that focused on a sitting U.S. senator.

Special Agent Chavez appears to have been first briefed on the case between July 17, the date CREW says it made its FBI referral, and August 1, 2012, the date of the first email from Chavez to Williams that was included in the online dossier.

Williams responded Aug. 25, focusing on the young ages of the girls involved.

“My main concern is the protection of my sources’ identities,” he wrote. “They are, as you may know, young prostitutes involved in those activities with senator Menendez and his friend Dr. Salomon Melgen.”

He also asked for the FBI’s help to ensure “that some social institution would assist these minors involved in their reinsertion to society.”

“About the girls, you may have the information I passed to CREW with some of their names. Not all the participants in those private parties are aware that some of the girls sharing [sex] with them are underage; others were minors some time ago, being already part of this circle. My point is that not knowing that, does not exempt them from their responsibility.”

Through Sept. 12, the documents indicate, Chavez investigated Williams’ claims and determined that they were sound.

“As far as the information you have provided, we have been able to confirm most of it,” Chavez’s Sept. 12 email reads. “We know that you are providing accurate information. … We are on the right track but we do need to meet in person. I would not like for the information you have to get stale and lose the opportunity to bring the people who abused these young ladies to justice.”

In an email dated 10 days later, Williams produced the names of four women, all of them over 18, who he said participated in the Menendez sex parties at Casa de Campo. Those four were not among the women TheDC interviewed for the Nov. 1 story.

Two days after that story was published, the documents show, Williams emailed Chavez to say that the videotaped interviews were consistent with what he knew about the prostitutes Sen. Menendez frequented in the Dominican Republic.

“I can’t say I have any doubts about the truthfulness of their testimonies,” he wrote on Nov. 3, while emphasizing that his interest was primarily centered on the underage girls involved.

“My purpose is to do justice to the minors sexually involved with Senator Menendez and not to play politics,” he wrote.

By Nov. 24, Williams was claiming to “have in my hands additional evidences of Senator Menendez’s participation in activities with underage and young prostitutes.”

The emails indicate that as Christmas neared, Williams was reluctant to meet Chavez in person. A similar pattern developed quickly between Williams at CREW, where Carrie Levine pressed him for details and asked for phone meetings but got neither.

Much of the online dossier is unconfirmed and may ultimately be unconfirmable. But an additional source, unrelated to the documents, confirmed to TheDC on Thursday that ABC News was working on the Menendez story as late as mid-October.

The emails in the dossier themselves do not establish that “Peter Williams” is male or female, American or foreigner, well-intentioned or nefarious. They also do not, by themselves, prove Menendez engaged in illegal or unethical conduct.

But the existence of an FBI investigation is consistent with what TheDC learned in November from the women who spoke on camera about the senator.

A retired FBI agent speaking on background said Thursday night that it was unlikely such an investigation would be handled by a single case agent. But he said that since most of Melgen’s flights to La Romana International Airport in the Dominican Republic originated in Palm Beach, Fla., the Miami Field Office was the logical FBI office to handle the case.

He would not speculate, however, on whether any inquiry into Menendez’s trips abroad was likely to have been completed, and the file closed, nearly six months later. It would depend, he said, on the believability of witnesses and their willingness to cooperate.

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