The federal grand jury investigating Sen. John Ensign (R-Nev.) is casting a wide net that will include the National Republican Senatorial Committee (NRSC), the Ballot Box has confirmed.

"The NRSC has responded appropriately to questions concerning matters related to the 2008 election cycle timeframe," Sean Cairncross, the NRSC's general counsel, said in a statement.

On Wednesday, the Las Vegas CBS affiliate KLAS-TV reported that several local businessmen who had dealings with Ensign and his staff dating from January 2008 were subpoenaed by the Justice Department.

The Nevada subpoenas sought "any and all records; including emails, phone calls and calendars," according to KLAS.

NRSC officials declined to comment specifically on what was asked for, but it's likely investigators requested similar records from the campaign committee.

Ensign headed the NRSC during the 2008 cycle. He's being investigated for helping former aide Doug Hampton secure lobbying work after conducting an affair with his wife.