(Recasts with denial of danger, box found)

RIO DE JANEIRO, Brazil, Nov 21 (Reuters) - Police in Rio de Janeiro on Friday recovered bacteria samples stolen in the hijacking of a biologist's car and doctors said that diarrhea, not typhoid fever or cholera, had been the main risk.

Initial police reports had said the stolen box contained samples of cholera and typhoid fever, prompting authorities to issue an alert.

In fact, it held samples of skin- and intestinal-borne bacteria such as staphylococcus and salmonella.

Police said they found the box with intact ampuls in a telephone booth in the Rio suburbs after an anonymous call. The abandoned car was found earlier on Friday in a shantytown.

Delia dos Prazeres, a researcher with Brazil's biology research authority Fiocruz, was taking the samples to a conference when she was carjacked at gun point on Thursday night.

She said she may have caused a misunderstanding about how dangerous the samples were because she was still in shock after the robbery.

"I was in the car with a 4-year-old, my 80-year-old mother, government property and my sister, and we all had guns pointed at our heads. I was upset after the robbery. Maybe if I had used different terms I wouldn't have been misinterpreted," she said.

Fiocruz President Paulo Buss said the samples would not have caused a problem if the box had been open but if a person tasted them "there's a 99 percent chance that he or she will have diarrhea."

Police said the criminals had obviously been after the car and did not know about the bacteria. Armed robberies are frequent in crime-ridden Rio, which is one of the world's most violent cities.