A bioweapons expert under scrutiny in last fall's anthrax attacks made a public statement Sunday to deny involvement with the deadly, microbe-filled letters and to proclaim himself a "loyal American."

"I love my country," Dr. Steven J. Hatfill said. "I had nothing to do with the anthrax letters and it is terribly wrong for anyone to contend or think otherwise."

After "one of the most intensive public and private investigations in American history, no one has come up with a shred of evidence that I had anything to do with the anthrax letters," Hatfill said in a statement he read outside his lawyer's Virginia office.

FBI spokesman Chris Murray told Fox News in response to the presser, "We are unaware of any FBI employee who has named a suspect in the anthrax deaths investigation" and "the FBI does not alert the news media to the service of search warrants."

Murray added that "credible allegations concerning the mishandling of evidence will be investigated thoroughly."

On Monday, a law enforcement official said under condition of anonymity that Hatfill remains a "person of interest" in the attacks because:

• The anthrax letters contained a return address of a nonexistent Greendale School in New Jersey. Hatfill once lived in Harare, Zimbabwe, where there is a school known as Greendale School. That school is actually named for Courtney Selous, the namesake of the Selous Scouts, who fought for white rule in what was then called Rhodesia. Hatfill has said he fought with the Selous Scouts.

• Officials found the draft of a novel about a bioterrorism attack on Hatfill's computer at his Frederick, Md., home,

• In 1999, while working for a defense contractor, Hatfill commissioned a report looking at how anthrax might be sent through the mail. That report suggested there would be about 2.5 grams of anthrax in an envelope -- and that's what was in last fall's mailings.

On Sunday, Hatfill, who had an American flag pin affixed to his lapel, said he had cooperated fully with authorities only to have what he called defamatory information about him leaked to reporters. He said he understood that authorities and the media had to consider his potential involvement after the letters killed five and sickened more than a dozen people.

"This does not, however, give them the right to smear me and gratuitously make a wasteland of my life in the process," he said.

Law enforcement officials have described Hatfill, 48, as a "person of interest," not a suspect, and said he is one of about 30 people being examined.

On Sunday, a law enforcement official close to the case said the scientist has not "received any more attention than any other person of interest in the investigation."

Hatfill's name is the only to have emerged publicly in the investigation.

Since then, several questions have surfaced about Hatfill, including what appear to be exaggerations on his resume, his involvement fighting for white rule in the former Rhodesia and whether he lost his security clearance while working for a defense contractor.

Neither Hatfill nor his lawyer would answer questions about his past, and Hatfill took no questions from the media. But he did say that anyone's life can be "picked apart" for inconsistencies. "I do not claim to have lived a perfect life," he said. "There are things I would probably do or say differently than I did 10 or 20 or more years ago."

Hatfill emphasized that his background is in the study of viral diseases such as Ebola, not bacterial diseases such as anthrax.

He said he was routinely vaccinated against anthrax because of his work at the U.S. Army Medical Research Institute at Fort Detrick, Md., once home to the U.S. biological warfare program and repository for the Ames strain of anthrax that was used in the attacks. But he said he had not been inoculated since 1999 and had been susceptible to anthrax since 2000.

It is unclear how much residual protection he would have had from his earlier vaccinations.

Hatfill and his lawyer, Victor M. Glasberg, described in detail their efforts to cooperate with law enforcement, saying they had been met with leaks to the press, such as a copy of a novel about bioterrorism that Hatfill had stored on his computer.

Glasberg said Hatfill would not submit to another polygraph test.

The FBI has already twice searched his apartment, as well as his car, a storage locker in Florida and the home of his girlfriend, they said.

Glasberg said the most recent search of his home, on Aug. 1, was conducted by surprise with a criminal search warrant, although he was working to arrange a date for another voluntary search.

Soon after agents arrived, news helicopters were hovering overhead as FBI and Postal Service agents wearing protective gloves searched his apartment complex.

"The FBI agents had promised me that the search would be quiet, private and very low key. It did not turn out that way," Hatfill said.

The law enforcement official said Sunday the FBI would never give prior notice of a search if a warrant had been obtained. "That just isn't the way we do things," the official said.

Hatfill said he has been cooperating with the investigation since the fall, when two FBI investigators asked to interview him. He said he spoke with them in a "cordial and short" session and agreed to take a polygraph test, which was being administered to others. Hatfill said he was told by the examiner that he had passed.

Soon after, Hatfill said, accusations from a reporter about his involvement in the attacks led his employer, the defense contractor Science Applications International Corp, to fire him.

Hatfill then got a job with Louisiana State University's National Center for Biomedical Research and Training. But he was suspended with pay after the Aug. 1 search of his apartment complex.

Hatfill suggested that the FBI's interest in him stemmed from comments made by Barbara Hatch Rosenberg, a molecular biologist at the State University of New York.

For months, Rosenberg complained that the FBI was failing to pursue a prime suspect, whose profile is consistent with Hatfill's, though she declined to publicly name anyone. Hatfill said Rosenberg did name him in a meeting with Senate aides and FBI agents, and soon after that meeting, the FBI was pursuing him again.

"I have never mentioned any names, not publicly, not to the FBI, not to the Senate committee or staff, not to anyone," Rosenberg responded in a telephone interview. "I have never said or written anything that pointed only to one specific person. If anyone sees parallels, that's their opinion.

"The FBI went out of its way to make one ... name public. I presume they had some good reason for doing that. If not, I think it was reprehensible to do so. I always avoid names and I always avoid specifics."

She added that Hatfill "has been misinformed" about her role and that she has "a certain sympathy" for him. "He may be falsely accused and I don't think the FBI should do that publicly," she said.

The Associated Press contributed to this report.