JOHN EDWARDS GRAND JURY: BEHIND CLOSED DOORS

Inside the secret world of the John Edwards investigation!

John Edwards has reacted swiftly since our exclusive report last week revealed that a federal grand jury was investigating him for possible campaign finance violations related to paying his mistress.

The former presidential candidate phoned the mother of his love child, Rielle Hunter, assuring her she had nothing to fear, a close source told The ENQUIRER.

"Rielle is extremely concerned about being called to testify. She's a nervous wreck. But John has told her, 'You didn't do anything wrong, so you have nothing to worry about.'"

Four former Edwards campaign workers recently received secret subpoenas to testify in Raleigh, N.C., The ENQUIRER revealed.

Now, published reports in Raleigh, N.C., have confirmed that the grand jury - which has the power to bring charges - was recently seated.

The ENQUIRER also disclosed that the FBI and the Internal Revenue Service were involved in the investigation.

Blonde divorcee Rielle is fearful the grand jury could raise questions about the money she received from Fred Baron, the former national finance chairman for Edwards' failed presidential campaign, confided the close source.

 "Rielle Hunter is afraid the issue of whether she paid any taxes on the money she received from Fred Baron will come up," said the close source. "It was hush money, and she always believed any taxes on the money were somehow paid by him."

But Baron can't appear to testify as he died last fall.

For all the details pick up the latest ENQUIRER.