City Controller Alan Butkovitz and Brett Mandel, one of his two foes in the May 21 Democratic primary election, used a debate Thursday afternoon to accuse each other of ethical violations.

Mandel, who finished third in the 2009 primary for controller, claimed that Butkovitz is under investigation by the Philadelphia Board of Ethics for using brochures produced with city money in his campaign for a third term.

"Alan has been using his staff and his resources to produce materials that he distributes at campaign events as if they were political material," said Mandel, who later told reporters he based his claim on an account from one person who has been questioned in the investigation. Mandel refused to identify that person.

Shane Creamer, executive director of the Board of Ethics, said he could not confirm or deny if such an investigation was under way.

Butkovitz said he had no reason to believe he is under investigation. In the debate, he accused Mandel of improperly accepting a in-kind campaign contribution worth at least $40,000 from a volunteer who created  a web site.  Mandel has been touting the Budget Bulldog site, which allows users to search for information in the city's budget.

"Is there some exemption for Brett from ethics rules?" asked Butkovitz, who later explained that he hired a web designer to study Mandel's web site.  The designer put the value of the work at $40,000 or more, he said. Butkovitz said he is now evaluating whether to file a campaign contribution violation complaint against Mandel.

The third candidate in the race, Mark Zecca, continued to accuse both men of unethical behavior for meeting in February 2012 to discuss ways to avoid a contested election for controller. Both men say part of that discussion involved Butkovitz hiring Mandel, though no deal was ever reached.

The hour-long debate was taped and will air Sunday at 9 p.m. on Larry Kane's Voice of Reason show on the Comcast network.