A Democratic congressional candidate accused in a political ad of billing taxpayers for a call to a phone-sex line suggested he may have misdialed the number while trying to reach a state agency.

The ad that began airing Friday shows Democrat Michael Arcuri leering at the silhouette of a dancing woman who says, "Hi, sexy. You've reached the live, one-on-one fantasy line."

But Arcuri's campaign released records showing the call two years ago from his New York City hotel room to the 800-number sex line was followed the next minute by a call to the state Department of Criminal Justice Services. The last seven digits of the two numbers are the same.

Arcuri, the district attorney in Oneida County, said the ad was "clearly libelous" and threatened to file a lawsuit. His GOP opponent, state Sen. Ray Meier, described it as "way over the line."

At least seven television stations in Syracuse, Utica and Binghamton refused to run the ad, Arcuri said.

The ad's sponsor, the National Republican Congressional Committee, stood by the 30-second message. Spokesman Ed Patru insisted it was "totally true" and said Meier was not consulted.

The two candidates, who say they are friends, are running to fill the seat left open by the retirement of Republican Rep. Sherwood Boehlert. Political analysts have said the race is among the nation's most competitive.

Arcuri said he had "never seen such an unfair commercial. I have a 12-year-old daughter. She's going to have to go to school and hear other kids talk about this."

Robert Thompson, professor of television and popular culture at Syracuse University, called the ad "an egregiously stupid accusation."

Earlier in the week, both candidates said they were disappointed by the attack ads produced and funded by their national party committees. They said campaign-finance laws prevent them from screening the commercials.

One voter, Rosemarie Paladino of Utica, said she found such negative advertising so distasteful that she was tempted to avoid voting.

"But then I said, 'Wait a minute. I've got to exercise my right."'