A Polish doctor says she has been in "deep shock" since learning that a 91-year-old woman she pronounced dead woke up in a morgue several hours later.

The doctor -- identified in the media as Wieslawa C. -- said on TVN24 television Friday that she was sure the patient was dead after finding "no basic life functions" during a morning house call on Nov. 6.

She said she checked for a pulse on a forearm and neck arteries, listened for a heartbeat and the sound of breathing, and checked the pupils for reaction to light, but found none.  "If I had had doubts, I would have called the ambulance, done an electrocardiogram, but I was sure that the patient is dead," the doctor said.

The doctor examined the elderly woman, identified by the media as Janina Kolkiewicz, in the eastern town of Ostrow Lubelski after relatives noticed she was not breathing.

Some two hours after she was pronounced dead the woman was taken to the morgue.  Shortly before midnight, an undertaker who brought in another body noticed that Kolkiewicz was moving inside a bag she had been placed in.  Once it was opened, she complained of being cold and asked for hot tea, the media said. She was then taken home.

A spokeswoman for the local prosecutors, Beata Syk-Jankowska, told The Associated Press that she had never heard of such a case before, and that prosecutors are investigating whether the patient's life and health were endangered by the inaccurate death diagnosis.

They also are urging a regional court to void the death certificate that local authorities issued, which discontinued Kolkiewicz's benefits such as her pension.

"In the legal sense, the woman is dead, but in reality she is clearly alive," Syk-Jankowska said.

She said Kolkiewicz has required no hospitalization since being removed from the morgue and is now in good health.