Blanche's aristocratic mother intended to keep her locked up until she abandoned her relationship - but she never did

Loving the wrong man was a serious business in the past as the incredible story of a French young woman who was secretly locked up in a small room for 25 years shows.

In Paris 1876, 25-year-old Blanche Monnier was a typical socialite scrambling to find a suitor before it was too late. She fell in love with an older, broke lawyer, who her aristocratic mother disliked, and set her heart on marrying him.

Then, Blanche just vanished. Nobody in France saw her in public again. Her mother and brother mourned her, and went on with their daily lives. But behind the appearance, they were hiding a terrible secret.

Blanche Monnier was found inside a padlocked room, her bed covered in food and faeces. She was extremely malnourished, weighing just 55 pounds

Mademoiselle Blanche Monnier was held captive in a padlocked, tiny room for 25 years by her mother. She had suddenly vanished after falling in love with a broke lawyer

On 23 May 1901, the office of the attorney general of Paris received a mysterious, unsigned letter detailing the captivity of Blanche Monnier at the hands of her mother

On 23 May 1901, the office of the attorney general of Paris received a mysterious letter. The unsigned missive read: 'Monsieur Attorney General: I have the honor to inform you of an exceptionally serious occurrence. I speak of a spinster who is locked up in Madame Monnier's house, half starved, and living on a putrid litter for the past twenty-five years – in a word, in her own filth'.

Shocked by the letter, police decided to investigate the estate despite Monnier's family sterling reputation. A group of officers broke into the house, searched the premises and upstairs noticed a padlocked door. When they removed the lock, a horrifying smell filled their noses.

To their surprise, an extremely malnourished woman cowering on the bed, covered in food and feces, was squinting through the light she had not seen in 25 years. Blanche Monnier, now weighing just 55 pounds had been kept prisoner for a quarter of a century. She had not seen the light or another human being during that time.

Madame Monnier, who had won an award from the Committee of Good Works for his generous contributions to Paris, was arrested after the discovery of her daughter (right)

Madame Monnier died in prison 15 days later, after confessing to locking her beautiful daughter in the attic

A witness described the gruesome discovery: 'The unfortunate woman was lying completely naked on a rotten straw mattress. All around her was formed a sort of crust made from excrement, fragments of meat, vegetables, fish, and rotten bread.'

'We also saw oyster shells and bugs running across Mademoiselle Monnier's bed,' he went on. 'The air was so unbreathable, the odor given off by the room was so rank, that it was impossible for us to stay any longer to proceed with our investigation.'

Madame Monnier, who had won an award from the Committee of Good Works for her generous contributions to the city, was immediately arrested.

She died in prison 15 days later, after confessing the abysmal abduction to police. When her daughter refused to back down on her relationship with the lawyer, Madame Monnier locked her up in a tiny room until she gave in.

For 25 years, Blanche only ate scraps from her mother's meals. Her punishment continued even after the death of her lover in 1885.

Blanche's brother Marcel stood trial for helping her mother in the ordeal and was initially sentenced to 15 months in prison. He was later acquitted on claims that Blanche could have left at any time, but chose not to. He walked free to the horror of the crowd in the courtroom.