Gov. Robert L. Ehrlich Jr., saying he was "angry" about the actions of Joseph F. Steffen Jr., said he would consider asking the state prosecutor to look into his longtime campaign and congressional aide, who resigned Tuesday because of his postings about O'Malley on a Web site.
Insurance Commissioner Alfred W. Redmer Jr., for whom Steffen worked, said someone within his agency would investigate whether Steffen used his state computer and work hours to post the messages.
Redmer also called O'Malley and the mayor's father-in-law, Maryland Attorney General J. Joseph Curran Jr., to apologize yesterday for Steffen's actions.
"These are despicable lies. These are falsehoods," said O'Malley, a Democrat who is expected to run for governor next year. "I have always been faithful to my wife, from our first date until this date."
Ehrlich insisted that Steffen is a rogue state employee - not part of any kind of orchestrated GOP effort. He called on Steffen to tell O'Malley he is sorry.
Steffen appeared anything but contrite in messages posted on www.FreeRepublic.com late Tuesday, hours after his firing.
"Hell, this might even burnish my reputation," read one posting from him on the Web site that included the rumors about the mayor.
For the past 18 months, stories have swirled in Maryland political circles and on Internet chat sites claiming that O'Malley had engaged in an extramarital affair.
The rumors had not been reported in the mainstream media until the governor's office made Steffen's firing public late Tuesday. Steffen's dismissal came as The Washington Post was preparing to publish a story linking him to some of the postings.
But because the rumors were widely known, they have been considered a political liability for the mayor.
Some political observers say the rumors could work to O'Malley's advantage if voters believe Ehrlich had a hand in spreading them - something the governor has denied.
Speaking before a swarm of television cameras and reporters outside City Hall yesterday morning, the O'Malleys said they were victims of a political smear campaign.
"When we first started hearing these rumors back about a year and a half ago, we figured it was a falsehood that would blow through," O'Malley said. "It became pretty apparent that this was something sustained, something orchestrated, something relentless, and something that others were working very hard to make sure would not go away."
Katie Curran O'Malley - a city District Court judge - appeared to be on the verge of tears at times, simply nodding her head when her husband, before addressing reporters, turned to her and asked, "OK?"
"I've always sort of considered myself a strong woman and a tough person, but I have to tell you from the bottom of my heart, this has been one of the most difficult things I've had to endure," she said.
Katie O'Malley said the rumors had taken a toll on the couple and three of their four children. The youngest, at 2 years old, isn't old enough to understand, she said. But their 13- and 14-year-old girls have been affected.
So has their 7-year-old son, William, she said, recalling what happened when he brought home his report card for a parent's signature last week. Only one parent had to sign, but William insisted that they both do, she said.
"He said to me, 'If Daddy doesn't sign it, then they're going to think that we're in a divorce,'" she said. "And I just looked at him and my heart broke that this poor, 7-year-old kid has to worry about these lies."
Neither the mayor nor his wife, who refused to take questions, explicitly blamed Ehrlich for the rumors.
But Stephen Kearney, O'Malley's communications director, suggested that Steffen had the Ehrlich administration's support. Kearney told reporters that Steffen was "leisurely" cleaning out his desk at his state office late yesterday morning.
"Contrast that with the way people are usually removed from government, which is quite different," Kearney said.
In an Internet posting in December, Steffen said he had made Ehrlich and Lt. Gov. Michael S. Steele aware of the conservative Web site, although he does not say he alerted the men to his O'Malley messages.
The governor said he first heard about Steffen's postings Tuesday night, when Ehrlich Communications Director Paul E. Schurick called him.
"There were two things wrong here," Ehrlich said. "One, the act itself. And two, the act on state time with state equipment."
Some of the messages appear to have been posted during work hours - though it could not be determined whether Steffen was at work on the dates when the messages were posted.
Ehrlich said he would make all documents and e-mails Steffen sent from state computers public. Ehrlich also said he would consider asking state Prosecutor Robert A. Rohrbaugh to investigate.
Rohrbaugh declined to comment.
Ehrlich legal counsel Jervis S. Finney said the governor has asked him to determine how best to investigate Steffen's activities.
State Sen. Brian E. Frosh, a Montgomery County Democrat and chairman of the Judicial Proceedings Committee, said he wants the legislature to investigate Steffen's activities, as well as those of any other state workers participating in similar tactics. He said he wants a committee to be granted subpoena power to do the work.
Asked whether he wants the governor to testify, Frosh said: "We'll see where it goes."
Senate President Thomas V. Mike Miller said he welcomed further inquiry, but did not go so far as to say a committee should investigate.
"I don't know how many people were involved, but it was more than Steffen. Many more than Steffen," said Miller, who also said an injunction should be filed to prevent the destruction of Steffen's e-mails or documents "related to this cowardly conspiracy."
Redmer, the insurance commissioner, said he has taken steps to secure Steffen's computer.
Curran, who said his office would not be involved in any investigation because of the obvious conflict of interest, said he was satisfied that Redmer would conduct a fair investigation.
"He's a real decent person, and I truly believe that he was just offended that one of his employees was doing something that was just bad," Curran said. "And if there's something more he should do, he'll do it."
Sun staff writers David Nitkin, Andrew A. Green and Michael Dresser contributed to this article.