A spokesman for Republican gubernatorial candidate Bob Beauprez says information that's now the focus of a Colorado Bureau of Investigation probe came to the campaign through a confidential informant.
Democratic rival Bill Ritter has called on state investigators to look into how Beauprez's campaign accessed supposedly confidential documents to create a new attack ad against him.
CBI spokesman Lance Clem says information in Beauprez's TV ads against Ritter could only have come from a confidential police computer.
Beauprez spokesman John Marshall says the campaign attorney is cooperating with CBI but told the Rocky Mountain News it would be unethical to reveal the source of the secret information.
The ad criticizes Ritter's record as a district attorney and says he plea-bargained a case involving an illegal immigrant who went on to commit more crimes.
Ritter's campaign spokesman Evan Dreyer says tracking that case through public records would not be possible.
Ritter and Beauprez are vying to replace Gov. Bill Owens, who is stepping down because of term limits.
(Copyright 2006 by The Associated Press. All Rights Reserved.)