A WOMAN who dropped a mobile phone into her huge garden wildlife pond was overjoyed when local divers retrieved it for her before the battery could poison her fish and plants.

Sarah Allberry, 55, said she was worried the heavy metals from the battery would leach and kill the wildlife growing in her 10,000 gallon pond.

The Cirencester mother tried and failed to dredge the Sony smartphone out herself but ended up enlisting the help of amateur divers from Cirencester Dolphin Sub-Aqua Club Derek Ainsworth and John Ling.

Kitted out in the full diver's gear, John and Derek arrived at Sarah's home earlier this week to explore the pond and find her phone.

"We do it all voluntarily, " said diving instructor Derek, 65. "We have helped people who have lost things over the side of boats. Once we tried to help someone find a wedding ring in a lake."

After about 20 minutes in the pond, which used to be a swimming pool and is five foot five metres deep, John, 36, finally emerged with a very wet and battered mobile phone and handed it straight to Sarah.

"I researched online and found that a lithium battery can contaminate a 6,000 gallon pond and this one is 10,000 gallons," said Sarah. "The main thing for me was just getting it out of the pond. The phone battery is much larger than a lithium battery.

"I'm extremely grateful to Derek and John."