Relatives of a woman buried in an overgrown cemetery claim developers promised it would be cleared up.

The Croydon Guardian reported earlier this month how the desolate Netherne Asylum cemetery in Coulsdon had been left to be overtaken by five feet tall nettles and plants.

Horrified Wendy Mortimer, who visited the site in 2006 when she discovered her great-aunt was buried there, wrote to MJ Gleesons asking it to take care of the graves.

The developer, which purchased the cemetery when it turned the hospital site into luxury flats promised her “landscape” work would be carried out but it remains overgrown.

Wendy Mortimer’s great-aunt Francis Mabel Mortimer died at 20, and was buried on July 10, 1915.

The young woman suffered from epilepsy, which was not well understood in those days, and was brain damaged when she fell off a wall and hit her head, aged 12. She was sent to the asylum where she was classified “an idiot”.

Her great-niece, said: “I was a bit upset when I heard about that. "After a lot of research, we discovered where she was buried. "When we got to the cemetery it was in the same mess it is now. I was shocked and dismayed.”

The 53-year-old wrote to Gleesons and the reply on October 2006 from operations director Andy Kirkpatrick reads: “I shall personally visit the area during my next visit to the development and will arrange for any necessary remedial works to be carried out.”

She said: “If Gleesons can build a new village with modern houses, surely it can afford to clear the cemetery and make it viewable.”

Scott Chamberlin, managing director of Gleeson Strategic Land, said: “Until the article published in the Guardian on September 15, 2010, Gleeson has had very few enquiries from relatives over the 15 years or so the cemetery has been in our ownership, and so the company continued to allow the cemetery to return to nature.

“However, since that article was published, we are aware that there clearly is interest and consequently the company is currently considering whether it should adopt a different approach.”