METAIRIE, La., July 16 — Speaking for the first time since he acknowledged a connection to the so-called D.C. Madam a week ago, Senator David Vitter of Louisiana appeared briefly before reporters here Monday to apologize again and attack “political enemies” he said had spread falsehoods about him.

Mr. Vitter dropped out of public view a week ago after admitting that his phone number had appeared in a list of clients’ numbers kept by Deborah Jeane Palfrey, who is accused of running a prostitution ring in Washington. He missed major votes on Iraq in the Senate and made no public appearances, even as accounts of other relationships with prostitutes multiplied in the New Orleans news media.

After his initial apology, a woman convicted of running a brothel on Canal Street said Mr. Vitter had been a client, and another woman, identified by The New Orleans Times-Picayune as a prostitute named Wendy Cortez, came forward to say that she, too, had had a relationship with him when the senator was in the State Legislature in the 1990s.

These reports echoed longstanding rumors in Louisiana — which Mr. Vitter had vehemently rejected in the past — that he had had encounters with prostitutes.