MYSTERY surrounds the death of a 63-year-old horse breeder from Purton who had never been known to come into contact with asbestos but died from a cancer caused by the deadly mineral.

Susan Nelson had worked on the same farm near Berkeley all her life and experts could not find any trace of asbestos fibres in her lungs after her death.

But an inquest at Gloucestershire Coroner's Court heard that she had died from malignant mesothelioma, a lung cancer for which the only known cause is asbestos exposure.

It usually affects people who worked with the substance many years ago before its dangers were known.

Ms Nelson died at her home, the former Berkeley Hunt Inn at Purton on August 13 last year and is survived by her 91-year-old mother.

Gloucestershire Coroner Katy Skerrett heard that 90 per cent of malignant mesothelioma cases could be related to asbestos exposure.

But Ms Nelson lived all her life on the farm, which she took over from her parents and they had taken over from her grandparents.

The hearing was told that there could have been asbestos on the farm, but this had not been confirmed.

A post mortem examination carried out by consultant pathologist Dr John McCarthy found plural plaques in the lungs, which were indicators of asbestos exposure.

But analysis of lung tissue found none of the deadly fibres normally seen in such cases and the inquest heard this absence of asbestos occurred in only 10 per cent of mesothelioma deaths.

Dr McCarthy gave the cause of death as mesothelioma, which had caused bronchial pneumonia.

Mrs Skerrett had asked her officers to find out more about Ms Nelson's occupation and possible exposure to asbestos but they were unable to find any detailed work history.

Ms Nelson's GP Dr Peadar Walshe said she had suffered from Parkinson's disease from 2010, but did not suffer from respiratory problems until 2015.

She had suffered from a shortness of breath for three months and a biopsy found that she had mesothelioma.

He said she had no known exposure to asbestos although she believed there was some in the farm buildings.

Summing up, Mrs Skerrett said death could have been from natural causes or from exposure to asbestos.

She said: "The vast majority of these types of tumour are caused by exposure to asbestos, but against that, there were no fibres present and no features of asbestosis.

"I am unable to look at the occupational history and see how the cancer might have been caused, so I will record an open conclusion.”