RALEIGH, N.C. - The State Bureau of Investigation is probing campaign donations provided to North Carolina politicians by the video sweepstakes industry.

North Carolina Department of Justice spokeswoman Noelle Talley confirmed Wednesday the criminal investigation into possible public corruption, which she said began in 2013. Talley said the probe was prompted by requests from federal and state prosecutors in Raleigh.

Talley would not specify the targets of the investigation.

The Associated Press reported last year that political donations from Oklahoma gaming software magnate Chase E. Burns may have violated state laws prohibiting corporate money from "directly or indirectly" funding political campaigns.

The campaigns of Gov. Pat McCrory, House Speaker Thom Tillis and Senate leader Phil Berger gave to charity thousands in donations linked to Burns after he was charged with running an illegal gambling enterprise in Florida. The three Republicans, who are the state's three highest-ranking elected officials, have denied any wrongdoing in taking the donations from the software provider.

GOP lawmakers are currently proposing to remove the SBI from the supervision of Democratic Attorney General Roy Cooper and place the agency under McCrory's control.

"This is an example of the type of public corruption investigation we're concerned could be thwarted or repressed by not giving prosecutors access to an independent investigative team like they currently have with the SBI," Talley said.

McCrory spokesman Josh Ellis said Wednesday that the governor had no knowledge of the probe.

Anna Roberts, a spokeswoman for Tillis, said the speaker was also not aware of the SBI investigation.

"He has not been interviewed or subpoenaed and, to our knowledge, no staff member has been interviewed or subpoenaed," Roberts said. Tillis is currently a candidate for U.S. Senate.

In an interview Wednesday, Berger said he had no knowledge of the investigation, nor has he or any of his staff been questioned or subpoenaed by investigators.

Oklahoma's top law enforcement official said last year that the checking account Burns and his wife used in 2012 to make $235,000 in donations dozens of North Carolina campaigns contained the laundered proceeds of a criminal gambling enterprise.

Records show the money flowed to Tar Heel politicians from both parties, making Burns, who lives in Anadarko, Okla., the largest individual donor in the 2012 election cycle. In addition to the direct donations to lawmakers' campaigns, Burns sent $55,000 to groups affiliated with the North Carolina Republican Party.

In September, Burns pleaded no contest in Florida to two criminal counts of assisting in the operation of a lottery. As part of a plea deal, prosecutors dropped 205 felony counts against Burns, including racketeering and money laundering charges.

In November, Oklahoma Attorney General Scott Pruitt finalized a separate agreement in which Burns agreed to forfeit $3.5 million from bank accounts seized as part of the investigation. According to Pruitt, the money came directly from the "laundered proceeds" of Burns' sweepstakes software company, International Internet Technologies.

Court filings reviewed by The Associated Press show $1 million of that forfeited money came from a checking account in the name of the Chase Burns Trust - the same account used to send the donations to political campaigns in North Carolina.

Records show most of the checks to North Carolina politicians were mailed or hand-delivered by staff at Moore & Van Allen, a Charlotte law and lobbying firm where McCrory worked until just days before he was sworn into office in January 2013.

McCrory has said he never met Burns and knew nothing of the firm's lobbying work on behalf of Burns or his company.

At the time, lobbyists from several firms representing sweepstakes cafe operators were launching a coordinated effort to persuade North Carolina lawmakers to legalize and tax the games. The cafes continue to operate across the state, despite legislators passing three separate laws in recent years intended to outlaw them.