They said the woman's grown-up son and daughter had discovered the tiny corpses - believed to be newborns - on Saturday evening when they were looking for something to eat while their parents were away.

'They both decided to get a pizza and realised that the freezer had to be cleaned out because it was full of out-of-date food... It was then that they discovered the first bag,' police investigator Herbert Fingerhut said.

The two waited for their parents to come home from a weekend holiday at around 7pm on Sunday before confronting them.

The 44-year-old woman, her husband and their daughter arrived at a police station soon afterwards.

A police car was then dispatched to the detached house in the town of Wenden, about 100km east of Bonn.

Police discovered all three babies in plastic bags, one of which contained a newspaper dating back to 1988, leading investigators to believe that at least one baby died at around that time, Mr Fingerhut said.

The couple have two sons aged 18 and 23, and a 24-year-old daughter.

The woman has been placed under medical supervision because of her mental state and was to be questioned later, said prosecutors' spokesman Ewald Weinberger. The corpses will undergo autopsies.

Prosecutor's spokesman Johannes Daheim said police had determined that the three infants had not been stillborn, but did not say how old they were or what might have been the cause of death.

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

The find is the latest in a string of such cases in Germany in recent years.

Most notable was Sabine Hilschenz, in eastern Germany, who killed nine of her newborn babies and hid the remains in buckets and flower pots, as well as in an old fish tank at her parents' home.

The divorced, unemployed dental assistant told investigators she did not harm the children but left them to die after giving birth alone every time following heavy drinking.

She was found guilty of eight counts of manslaughter in 2006 and is currently serving a 15-year prison sentence. Last November, a 35-year-old woman from Erfurt was sentenced to 12 years' jail for killing two of her babies and hiding their bodies in a freezer.

Then, in December,a 31-year-old woman was arrested after police recovered the bodies of five children, aged between three and nine years, at a house in Darry, near the northern city of Kiel.

The same month, a woman was arrested in Plauen in eastern Germany on suspicion of killing three newborn babies to which she had given birth. The bodies were discovered in a trunk in the cellar, on the balcony and in a fridge.

AGENCE-FRANCE PRESSE, ASSOCIATED PRESS

TOWN IN SHOCK

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

MR PETER BRUESER, mayor of the town of Wenden