OLPE, Germany _ A 44-year-old woman has been arrested on suspicion of killing her own babies after her grown children found the bodies of three infants stashed in the family's freezer in a grisly discovery prompted by a search for frozen pizza.

Police confirmed the find Sunday night in the town of Wenden in the western state of North Rhine-Westphalia after the woman turned herself in.

The three infants are believed to have been born alive, but authorities were awaiting autopsy results to determine how they died.

The woman, her 47-year-old husband and three adult children _ two sons, aged 18 and 22, and a 24-year-old daughter _ have lived in the town in a single-family home since 1984.

The children discovered the frozen babies on Saturday afternoon while cleaning out the freezer while their parents were away for the weekend, investigator Martin Feldmann said.

The 18-year-old and his sister had been looking for a frozen pizza and came across a lot of expired food so decided to clean out the freezer, said Johannes Daheim, a spokesman for prosecutors investigating the case.

The teenager then found three identical packets on the bottom of the freezer and opened one and saw the head and arm of an infant that was wrapped in a hand towel, police said.

The children confronted their parents when they returned home Sunday, and the couple and their daughter then went to police together to tell authorities, Herbert Fingerhut, head of the police investigation, said at a news conference.

The overweight woman apparently concealed the three pregnancies, believed to have been in the 1980s, not only from neighbours but also her own family, Fingerhut said.

``It sounds unbelievable, but there are examples showing such things are possible,'' he said.

The news of the discovery took other residents aback.

``I've been mayor for 14 years, and this is definitely the worst day I've seen,'' said Peter Brueser. ``We will need a long time here to work through this.''

It was the latest in a string of similar cases in Germany.

In the worst case, a woman was convicted of manslaughter in 2006 and sentenced to the maximum 15 years in prison for killing eight of her newborn babies and burying them in flower pots and a fish tank in the garden of her parents' home near the German-Polish border.

More recently, police in February were called to a home in northern Germany where a dead infant was discovered in the cellar.

In January, a 28-year-old German woman was charged with manslaughter after the remains of three babies were discovered in her house and the home of a relative. That woman has denied killing the babies.