The Republican vice presidential nominee is being investigated for allegedly pressuring the public safety commissioner to fire a state trooper who was going through a custody dispute with Palin's sister. Palin eventually fired the commissioner.

Former Palin Press Secretary Meg Stapleton told reporters the investigation has been taken over by legislative "operatives" for the campaign of Democratic presidential nominee Barack Obama, CNN reported. The Obama camp responded by saying the allegation is "paranoia," and also denied sending staff to Alaska to help with the probe.

The investigation began on a bipartisan basis in July, CNN said. Friday, lawmakers voted to subpoena Palin's husband, aides and one records; Stapleton said Palin already has turned over e-mails that exonerate her to a state board, which should be in charge of the investigation instead of the Legislature.

Palin's office maintains the commissioner was insubordinate, asking Congress for money which had not been approved by the governor.