RENNES, FRANCE -- A French woman has filed a complaint against a baby formula manufacturer after her infant daughter allegedly vomited a parasitic worm the length of an adult index finger, police said Wednesday.

The incident came after another family allegedly found a living larva in a container of the same milk powder brand, Gallia, manufactured by French firm Danone.

Police in the northern region of Brittany told AFP the mother of a three-month-old child came in on Tuesday to file a complaint.

"In November, her three-month-old daughter had a high temperature," Saint-Malo police told AFP.

"She brought her to the emergency room, where she was treated. And several days later, she vomited a worm about six to seven centimetres long."

The mother told police the worm had been analysed at the hospital and was confirmed to be of a parasitic type.

She said she had decided to take action after she learnt via the media of two similar cases.

The daily newspaper Ouest France reported that a second complaint had been lodged in the Puy-de-Dome region in central France where the larvae was allegedly found, and a third similar case is suspected in the southwestern Landes region.

Danone said that without the containers having been returned for analysis, "several hypotheses could explain the presence of an insect", including substandard transportation or storage conditions.

Cecile Cabanis, the company's chief financial officer, told a press conference the formula is not exposed to air at any stage during the production chain.

"It travels through closed pipes and is conditioned under a protective atmosphere with less than two percent of oxygen, conditions in which it would be impossible for any living organism to survive," she said.