In a case that is baffling federal and state investigators, a 94-year-old Oxford woman was in critical condition Tuesday at Griffin Hospital in Derby after testing positive for the potentially deadly form of inhalation anthrax.

FBI investigators and Gov. John G. Rowland stressed that they would not be able to confirm Connecticut's first anthrax case until definitive test results were returned today by the Centers for Disease Control and Prevention. Two tests by the hospital and three by the state Department of Public Health, all conducted since Friday, returned results indicating anthrax.

``I'm hoping that our tests are wrong, and that the CDC will come back with a different result,'' Rowland said at an evening news conference in his Capitol office, hours after he was informed that state test results had come back positive.

``It's very difficult at this time for anyone to explain how the patient may have contracted anthrax,'' he said. ``We have no evidence that anyone sent the patient anything containing anthrax, and we have no evidence that the patient contracted the disease as the result of some criminal act.''

The woman, Ottilie W. Lundgren, was taken to Griffin Hospital Friday by a family member and was suffering from a fever and upper respiratory problems, said the hospital's president, Patrick Charmel. Although early suspicions were that Lundgren had pneumonia, a blood culture taken within hours of her admission found abnormalities that led doctors to test for anthrax. Results returned Saturday from the hospital's tests indicated the presence of anthrax, Charmel said.

Although Lundgren was put on antibiotics, her condition deteriorated quickly, Charmel said. The state Department of Public Health was notified over the weekend and conducted its own, more sophisticated tests Monday. Results of the three state tests came back positive Tuesday for anthrax, Charmel and state officials said.

``I myself am praying for [the tests] to be wrong,'' state Health Commissioner Joxel Garcia said. ``I love my lab, but I would love that they were wrong.''

Rowland said the FBI and state police had sealed off the woman's home Tuesday and launched an investigation, including interviews of relatives and friends. By late Tuesday night, investigators from several agencies were on the scene. Lundgren lives alone, has not traveled recently and had a ``limited routine,'' said Rowland, who did not identify the woman by name.

``I'm not only shocked, I'm very concerned,'' the governor said. ``I'm shocked because I'm trying to figure out how it occurred. ... It is an anomaly, based on a person in their 90s, in a somewhat remote location, not related to a federal building'' or other government offices.

Rowland said that the CDC had picked up a specimen for testing Tuesday, with results expected sometime today and that a team of CDC investigators was on its way to Connecticut Tuesday night.

Lundgren's niece, Shirley Davis of Woodbury, said she was stunned by the preliminary diagnosis on her aunt, a former legal secretary who was widowed in 1977. Davis, who said she stopped to check on Lundgren two or three times a day, said her aunt rarely left her Edgewood Road house except to attend church or visit the beauty parlor. Davis said she had taken her aunt, whom she described as weak and disoriented, to the emergency room Friday.

``I just don't know how it could have happened,'' Davis said. ``I handle her mail and pay her bills. ... I nearly fainted when they told me at the hospital that they suspected anthrax.''

If inhalation anthrax is confirmed, Lundgren would be the 11th person reported with that form of the disease, which is more serious than the skin form. Of the 10 people previously identified as infected -- in Florida, New York, New Jersey and Washington, D.C. -- four have died. The most recent death was that of Manhattan hospital worker Kathy Nguyen, 61, on Oct. 31. Investigators still have not been able to determine how Nguyen contracted anthrax.

Two federal law enforcement sources in Connecticut expressed skepticism late Tuesday that Lundgren's illness would turn out to be a genuine case of anthrax. The sources, who spoke on condition of anonymity, said that cases of multiple ``false positives'' had occurred elsewhere around the country, only to be debunked by the final CDC testing. They also said that what little was known about the woman's background and habits made her an unlikely candidate for exposure.

FBI officials said they were awaiting CDC results before declaring Lundgren's case to be, in fact, anthrax-related.

``It's absolutely not a confirmed case,'' said FBI Special Agent Lisa Bull, adding that ``some questions were raised'' that need to be cleared up by the CDC tests.

Rowland said he had not been made aware of any concerns about possible contamination at the state's postal facilities. Oxford mail is routed through a Wallingford distribution center and sent to the Seymour post office, where mail carriers begin their routes, said postal service spokesman Jim Cari. He said the Wallingford facility was tested on Nov. 11 and found to be free of anthrax.

Rowland urged residents not to be ``overly alarmed'' and said he had no plans to order additional state security at any facilities. He decided to go public with the information after learning that Griffin Hospital officials planned to notify their employees Tuesday, anticipating that the news would start leaking out, aides to Rowland said.

Neither postal workers nor hospital employees were being tested for anthrax exposure Tuesday night, as officials waited for the CDC results.