CBS News can confirm that the FBI is looking in to the claims, including one that the Senator solicited prostitutes while on a trip to the Dominican Republic – a country where prostitution is legal. So far the investigations have not been able to prove that Menendez did anything wrong, but with every charge, the pressure is growing on Menendez.

The Miami herald dispatched a team of reporters to the country to investigate. “Trying to find someone this many months after the fact based on all the sketchy allegations and the unclear claims, its really difficult. It’s a cold trail,” said Marc Caputo, a political writer for the paper. “But that’s only part of what’s become a steady drip of allegations against Menendez.”

The FBI and the Senate Ethics Committee also are investigating Menendez’s relationship with Florida doctor Salomon Melgen, a close friend and campaign contributor. Last month, the FBI raided Melgen’s West Palm Beach office after the doctor was accused of improperly billing Medicare nearly $9 million. He is fighting those charges.

Menendez’s office confirmed it contacted U.S. health agencies to see if the charges against Melgen could be disputed and he’s repeatedly denied interfering with any investigations.