LYOND, France (AFP) - A Frenchwoman who has admitted to drowning two of her own new-born children and storing the corpses in her freezer has been imprisoned and placed on suicide watch, judicial sources said on Wednesday.

The 32-year-old, identified as Ms C, has been in custody since Sunday, when the babies' bodies were discovered by police who had been called by her partner to their home in the town of Amberieu in eastern France.

If autopsies confirm Ms C's testimony that the babies were drowned alive, she is expected to be charged with aggravated murder as she has a previous conviction for infanticide.

She was sentenced to 15 years in prison in 2005 for killing a baby she had given birth to in 2002 after a concealed pregnancy. Having been held for three years before her trial, she ended up serving eight years of her sentence before being released in 2010.