A former Republican campaign worker claims that President Bush's top political adviser, Karl Rove, asked her to find evidence that the Democratic governor of Alabama at the time was cheating on his wife, according to an upcoming broadcast of "60 Minutes."

Jill Simpson, who has long alleged that Rove may have influenced the corruption prosecution of former Gov. Don Siegelman, makes the claim against Rove in a broadcast scheduled to be aired Sunday, according to a statement from CBS.

Simpson testified to congressional investigators last year that she overheard conversations among Republicans in 2002 indicating that Rove was involved in the Justice Department's prosecution of Siegelman. She has never before said that Rove pressed her for evidence of marital infidelity in spite of testifying to congressional lawyers last year, submitting a sworn affidavit and speaking extensively with reporters.

Rove's attorney, Robert Luskin, denied the allegation.

"Mr. Rove never made such a request to her or anyone else," Luskin said in an e-mail to The Associated Press. "Had '60 Minutes' taken the trouble to contact Mr. Rove before circulating this falsehood, he would have told them the same thing."

In its statement, CBS said Rove declined to speak with "60 Minutes."

The statement says Rove approached Simpson at a 2001 meeting, when Siegelman was still governor.

"Karl Rove asked you to take pictures of Siegelman?" reporter Scott Pelley asks.

"Yes," Simpson replies.

"In a compromising sexual position with one of his aides," Pelley says.

"Yes, if I could," she responds.

Simpson said she is speaking out because Siegelman's seven-year sentence on corruption charges bothers her, the release said. She said she found no evidence of an affair.

Siegelman, who was elected in 1998 and narrowly lost re-election in 2002, was convicted last year on federal bribery and corruption charges. The prosecution stemmed from his appointment of former HealthSouth CEO Richard Scrushy to an influential hospital regulatory board in exchange for Scrushy arranging contributions to Siegelman's campaign for a state lottery.

The Justice Department — as well as the career prosecutors who handled the case — have insisted that politics played no role in the case, emphasizing that Siegelman was convicted by a jury.

Democrats on Capitol Hill, however, have been looking into the case as part of a broader investigation into political meddling by the White House at the Justice Department. Also, more than 40 former attorneys general have asked for a congressional investigation into the case.