The tragic tale of an-eight-year-old boy who died in 1915 at the Netherne lunatic asylum has been revealed through the diaries and memories of a devoted nurse.

Elizabeth Martin cared for little Jean Barboni the eight-year-old son of a French physicist living in Carshalton Beeches.

The little boy ended his days in the Netherne Asylum, his neglected grave now lies among more than 1,300 others, overgrown with nettles and weeds.

His death haunted his nurse so much, she was still greatly affected by it when she shared her memories with her niece Edith Kelly 30 years later.

Mrs Kelly contacted the Croydon Guardian to share her aunt’s memories and her outrage at the state of the neglected cemetery, which has been left to nature by the developers MJ Gleeson which bought the site and turned the hospital in luxury flats.

She said her aunt met the Barbonis at mass at a nearby convent.

“They had just moved into the area and had a baby son who was mentally defective (that was my aunt's term) and asked if Elizabeth could help them as she was a nurse.

“They lived in a large new house near Carshalton Pond but after a few years they moved up to Hill Road, where Mrs Barboni gave birth to another son, Pierre.”

Edgard Barboni was an officer in the French army and a physicist who was engaged in top secret chemical warfare work during the First World War.

Mrs Kelly said: “My aunt said that Jean Barboni needed so much nursing care that they could not cope and he was admitted as a private patient in a house for mentally subnormal children at the Netherne Hospital.”

Her niece said: “I discovered from looking through one of her diaries that she felt she had contributed to Jean’s death by allowing him to be put in a Pauper Hospital where he contracted TB.”

Shortly after his death, his parents returned to France with their younger son Pierre and Elizabeth Martin religiously tended his grave.

Mrs Kelly said: “For as long as I could remember, she regarded him as her own child. I suppose the emotional involvement must have been that much greater because the parents were in France and possibly never visited the grave again.

“I suppose his grave became a shrine. That's why I feel so angry that the cemetery has been neglected.”

MJ Gleeson have received a number of complaints about the state of the cemetery and have promised to look at the site .