McCain wants former Republican Rep. J.D. Hayworth to release names of contributors helping Hayworth pay off legal bills from his preparations for a possible Justice Department investigation centering on convicted GOP lobbyist Jack Abramoff, The Arizona Republic reported Monday.
A McCain ally said the McCain campaign is not alleging wrongdoing but Hayworth should be open with voters.
"It's all absolutely legal, but you're now a candidate for the United States Senate, and who contributes money to you is something that the public has an absolute right to know," Rick Romley, former Maricopa county Attorney, said.
Hayworth's campaign says McCain is trying to smear the six-term congressman with allegations about his links to Abramoff. Hayworth was never charged in the influence-peddling scandal that landed Abramoff in federal prison, the Republic said.
A campaign Web video released Wednesday by the McCain camp called on Hayworth to "come clean on your secret Abramoff trust fund."
The Arizona GOP Senate primary is scheduled for Aug. 24.