“I’m not going to respond to the fallacious allegations of your story,” Menendez told the Daily Caller on Monday when a reporter caught up with him on a train in Washington.

At the time, Menendez had just stepped into the national spotlight along with Sen. Marco Rubio, R-Fla., and six other senators who are hammering out a highly watched immigration plan that is the talk of Washington.

Rubio is one of the few big-name Florida politicians who has not received campaign money from the Melgens, who have contributed to Sen. Bill Nelson and Reps. Debbie Wasserman Schultz, Joe Garcia, Ileana Ros-Lehtinen and Mario Diaz-Balart, among others.

The FBI would not comment on the emails, and the agent, Regino Chavez, did not return calls or emails. But sources told The Miami Herald that the emails are real.

The emails from agent Chavez show that he tried to find out what happened. But the tipster, who went by the name “Peter Williams,” refused to talk to him by telephone or meet him face to face.

Chavez contacted the tipster Aug.1, 2012, after the group Citizens for Responsibility and Ethics in Washington referred the case to the FBI. The tipster would not meet or speak by phone to CREW or to an investigative reporter, either.

“As far as the information you have provided, we have been able to confirm most of it,” Chavez wrote on Sept. 12. “We know that you are providing accurate information.”

But it is not clear what that specific information is because Chavez was unable to interview the alleged prostitutes. Over the months, Chavez tried to meet or speak with the tipster, but had no luck.

Then, on Nov. 1, the agent wrote the tipster again and drew attention to the Daily Caller interview with the alleged prostitutes.

“I think we are at the point where you and I need to communicate over the phone so that we can move faster,” he wrote.

No luck.

Amid the suspicious circumstances of the complaints, Democrats have tried to characterize the reports about Menendez and Melgen as a right-wing smear job.

Senate Democratic leader Harry Reid refused to comment on the possibility of an FBI investigation when he was asked Tuesday about the case.

Said Reid: “Always consider the source. All anyone here has to look at is the source where this comes from.”

But the two-day raid of Menendez’s longtime friend shows that an investigation is ongoing.

Just after 2:15 p.m. Wednesday FBI and HHS agents began hauling cardboard boxes out of Melgen’s West Palm Beach 45th Street eye-care center and loading them into a white utility van in front of the office. They were continuing the search that started Tuesday night.

Michael Leverock, spokesman for the FBI’s Miami office would not comment on what was being taken out of Vitreo-Retinal Consultants Eye Center or why the FBI was there.

“We are conducting law enforcement action at this location,” said Leverock.

The FBI also searched the eye doctor’s other clinics, in Delray Beach and Port St. Lucie.

At the scene in West Palm Beach, agents, some from the Office of the Inspector General of the federal Health and Human Services department, formed a single-file line each holding at least one box and rotated back in to get more.

As soon as the boxes were loaded, the glass double doors of the eye care center, which were propped open with red poinsettias, were closed. The van remained in front of the eye care center.

Earlier in the day, an agent went to his car to retrieve what looked like a crow bar. Some time later a locksmith from Pop-A-Lock showed up and was escorted in by an agent.

The locksmith came out once to get a drill.

One patient, Anthony Jordan, showed up for fis 2:30 pm appointment and was surprised to find crime scene tape at the clinic site.

“I wasn’t sure if they called and cancelled,” he said. “Guess I am not having my appointment.”

Miami Herald staff writer Luisa Yanez contributed to this report.