The grand jury testimony is another indication that federal investigators are looking into some of the same issues as the State Board of Elections, which, last week, held hearings into the alleged violations by House Speaker Jim Black and other state leaders.
"This is serious business," said former federal prosecutor Dan Boyce. "Any time you're talking about the federal grand jury, it's serious."
Boyce believes federal investigators will try to build on what nearly a dozen optometrists told the elections board: that they wrote incomplete checks and sent them to a leader of their industry's political action committee.
Records show the payee's name and date were often added to the check months later when they were passed out to legislative candidates.
At last week's hearings, when asked about the checks, Black admitted he filled in the payee line on some of the checks and funneled them to his political ally, former state lawmaker Michael Decker.
Unlike, the elections board's hearings, grand jury testimony is confidential. Former prosecutors, however, have told WRAL that they think investigators are trying to find evidence of political payoffs -- something Black has adamantly denied.
"Campaign contributions are legal, but when you cross that line of saying, 'I'll give you money or I'll give you something in exchange for some official act,' that's illegal," Boyce said.
The elections board ended its hearing last Friday, referring the matter to Wake County prosecutors to investigate allegations involving Decker, as well as Michael Scott Edwards, the former head of the N.C. State Optometric Society's political action committee.
Decker, who was supposed to testify before the board, declined to testify during the hearing, citing his Fifth Amendment right against self-incrimination.
The elections board is scheduled to hold a hearing next month on video poker contributions -- something that a federal grand jury has already been investigating.