A former lifeguard died mysteriously in her sleep aged just 44 after she began self medicating with powerful painkillers to deal with a rare hearing disorder.

Adrienne Crowder had been diagnosed with Ménière’s disease, which caused her to lose her balance and fall over and injure herself. She was found dead at her home in East Kilbride, last April with toxic levels of morphine in her system.

An unsigned and undated police report said packets of the prescription-only painkilling drug cocodemol were found on the floor next to Miss Crowder - but although 160 tablets were missing from a haul originally containing 220 pills, an inquest was told officers did not investigate where the drugs had come from or where they went.

It emerged in the three weeks before her death, Miss Crowder, originally from Bolton, Greater Manchester, had been in a road traffic collision and needed crutches to get around.

A hearing in Bolton was told Miss Crowder had grown up in Bolton and worked as a lifeguard at a leisure centre in Wigan before moving to Scotland to be with her new partner.

But she had various health problems and aged 19 she was diagnosed with epilepsy and then in 2007 was told by doctors she had the heart condition dilated cardiomyopathy. She began taking medication for it, frustrated that it impacted her sporty lifestyle.

More recently she was diagnosed with Ménière’s disease, which caused her to suffer from vertigo, hearing loss and tinnitus and suffered from sciatica.

Recording an open conclusion, assistant coroner Tim Brennan said: “This court was hampered by the quality of evidence, and the limited information that was received from the procurator fiscal office in this case.

It means regrettably that mystery still envelops the precise circumstances of Adrienne’s tragic early demise.”