HARRISBURG — The state's investigation into bonuses awarded to Pennsylvania legislative staffers is widening as six more aides have been subpoenaed to testify before a grand jury, a newspaper reported Sunday, citing unidentified individuals with knowledge of the inquiry.

With the latest subpoenas, at least 14 staffers have now been summoned by Attorney General Tom Corbett to testify before a grand jury examining whether public bonuses were awarded for political campaign work last year, The Philadelphia Inquirer reported.

All those called are Democratic employees of the state house, and top Democratic leaders say that is no coincidence.

House Democrats awarded $1.9 million in year-end cash bonuses to 678 staffers, and they believe that glaring examples of bonuses handed out on the GOP side are being brushed aside by Corbett, a Republican.

"This is an Alberto Gonzales-like investigation," said T.J. Rooney, chairman of the Pennsylvania Democratic Party. "It seems that he has ignored the fact that red flags exist on his side of the field and is only pursuing the blue flags on our side."

Corbett told The Inquirer he could not comment on grand jury matters, citing secrecy rules.

But he said he was "extremely disappointed that before the results of the investigation have been announced that Mr. Rooney, as the leader of the Pennsylvania Democratic Party, has resorted to name-calling."