John Edwards may be in a bind.

The former North Carolina senator and presidential aspirant is being investigated by a federal grand jury for possible campaign-finance violations related to money he gave his former mistress and campaign worker, Rielle Hunter. Well, apparently Hunter’s worried and wonders just what other dirty laundry may come out, particularly since four ex-Edwards campaign workers were reportedly subpoenaed to testify. And the National Enquirer reports that Edwards himself called Hunter, who the tabloid says is the mother of his illegitimate child, to calm her fears.

"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,’" a source told the tab.

Hunter received money from Fred Baron, Edwards’s former national finance chairman, and apparently worries the feds will look into whether she paid taxes on that money – which she reportedly did not.

More details on the investigation are so far hard to come by. That’s surprising, since it’s such a juicy story. The Enquirer seems to be the only one trying to stay on top of it!