Could the worst be still to come for John Ensign?

An expert consensus may be forming that the Justice Department will likely launch a criminal investigation into the philandering Nevada senator and his relationship with Doug and Cynthia Hampton.

"I don't see how they cannot look at this case," Stan Brand, a Washington lawyer and ethics specialist told Politico.

"This may be a hard one for them to take a pass on," a former Justice Department prosecutor told the news site. "I think, at a minimum, a grand jury will be empaneled, and Ensign and Hampton will be called in to testify."

And Peter Zeiderberg, a former Public Integrity prosecutor for the department, who helped lead the Scooter Libby prosecution, told Fox News that a criminal probe of Ensign "is likely."

The department will reach a decision "within weeks" reports Politico.

The bronzed GOP senator has already admitted to having his wealthy parents pay almost $100,000 to the Hamptons soon after Cindy Hampton stopped working for his PAC. Some have suggested that the payments could be considered an unreported in-kind contribution.

Ensign also reportedly helped set up Doug Hampton as a lobbyist and recruited clients for him. He then reportedly directed his staff to remain in contact with Hampton, knowingly flouting a law which forbids lobbyists to have contact with their former Hill offices for a year after leaving. Ensign also reportedly took several actions that benefited Hampton clients, after requests from Hampton to his office.

The good-government group Citizens for Responsibility and Ethics in Washington has filed a formal complaint urging DOJ to investigate Ensign. The Senate Ethics committee has said it is already probing the matter.