A 30-year-old French mother was detained and placed under formal investigation Wednesday in the eastern French commune of Pontarlier, located near the Swiss border, after it was revealed that she had killed her three infants by suffocating them with a towel.

The mother acknowledged having ''disposed of'' her three babies in the context of pregnancy denial, including an infant born in the end of 2015 and a set of twins born in November 2016, French daily Le Parisien reported.

''She suffocated the infants to death after giving birth alone and in secrecy. The babies were obviously viable as they cried. After murdering them, she hid the corpses in the attic of her house,'' Edwige Roux-Morizot, public prosecutor from Besançon, reported.

The event surfaced after the father of the infants, suspicious of the heavy smells emanating from the attic, discovered the bags containing the corpses. He then reported his findings to police after seeing the strong, strange reaction of his wife, without checking the contents of the bags in question.

The 36-year-old husband of the woman was set free, as he did not know about the birth of the babies.

''The suspect, who in her psychological state is denying everything outside her family, was unwilling to become pregnant and have more children,'' the prosecutor said.

The prosecutor also noted that the woman, who is already the mother of two children aged three and seven, will undergo a thorough psychiatric check.

Charged with aggravated voluntary homicides, the suspected woman will appear Monday before court in a first audience.