COLUMBUS, Ohio (AP) _ Mayor Dana Rinehart launched a citywide honesty campaign last year that drew national attention, but now he's admitted that he lied about having an extramarital affair.

''You find somebody whose life is perfect, and let him lead the campaign. My life is not perfect,'' Rinehart said Monday in an interview with The Associated Press.

Until last weekend, Rinehart called reports of his affair with Human Services Director Brenda Dodrill an ''outhouse rumor.''

But in an interview Saturday with a radio station, the 44-year-old mayor acknowledged the affair.

''I flat wasn't telling the truth,'' Rinehart told WTVN-AM.

''I'm not proud of what's happened, but I'm not unhappy about it,'' Ms. Dodrill said in a newspaper interview published today. ''As far as a personal relationship, we'll have to see what happens. We don't have any plans.''

She said her involvement with Rinehart was a private matter, adding, ''I'm not an elected public official.''

Rinehart said Monday he lied to protect innocent people.

''It was not truthful. I'm sorry about that. ... I felt that my willingness to take that risk, knowing full well that someday I would have this conversation with a reporter - I would pay for this. I was trying to protect them,'' he said.

Rinehart and his wife, Carol, have two children.

Rinehart, a Republican in his second four-year term, announced July 22 that he would not seek another term, saying family, financial and political reasons influenced his decision.

The following month, he and his wife announced they had separated.

Now he says he will not resign and will decide in December whether to seek re-election in 1991.

Rinehart was at the forefront of a 1989 campaign called ''Take an Honest Look.'' He established the Columbus Commission on Ethics and Values after an incident in which the rear doors of an armored car flew open, spilling thousands of dollars onto a downtown highway.

Motorists grabbed the cash and most of them kept it.

Newspaper advertisements and broadcast commercials urged residents to ''examine honesty as it affects our daily lives.''

A former Watergate conspirator, the Rev. Jeb Stuart Magruder, was chairman of the commission. He has since moved from Columbus to Lexington, Ky., to become minister of the First Presbyterian Church.

Like Magruder, many members of the commission, which included City Council members and religious, business and education leaders, declined to comment about the matter.

But John S. Christie, who served on the commission during the campaign, said he didn't think the affair would hinder Rinehart's effectiveness as mayor.

''I have always found the mayor, as an administrator on city business, to be a very good mayor,'' said Christie, vice president for corporate development at Battelle Memorial Research Institute. ''Even though there are personal problems, I still think he has the ability and the wherewithal to keep high standards as it relates to running the business of the city of Columbus.''

Rinehart, 44, said he would continue to serve on the commission.

Ms. Dodrill, 32, began working at City Hall in 1986 as a $28,205-a-year personnel specialist. She was appointed to her post last year and makes $66,685 a year.

Ms. Dodrill's husband, Douglas Matteson, sued for divorce on Oct. 30 and later filed court documents alleging an affair between Rinehart and Ms. Dodrill.

He alleged that Rinehart and Ms. Dodrill had been seeing each other since March. They were together ''a couple times a week'' and went out of town together for weekends at least twice, according to the documents.

Ms. Dodrill had not reported to work since the relationship was revealed and is on vacation this week.

It is not the first sex-related controversy involving Rinehart. In 1978, when Rinehart was Franklin County treasurer, family baby sitter Vicki Rae Pardue accused him of sexually assaulting her.

Ms. Pardue alleged that, while napping at Rinehart's home after baby sitting his children, she awoke to find him performing oral sex on her.

Rinehart denied the allegations. A county grand jury investigated but did not issue an indictment.