A little girl was so inspired by a fundraising day at her school that she decided to raise more money for the charity by herself.

Olivia Callaghan swam 5km and totted up more than £870 for the A-T Society, which supports those with the rare genetic disorder ataxia-telangiectasia.

The six-year-old is a pupil at Kingfisher Primary School in Chatham, which raised £542 with a day of activities for the cause.

The Pentagon Shopping Centre in Chatham, which has been supporting the A-T Society, was so impressed when it found out about Olivia’s swim, it agreed to match the £437 she raised.

Centre director Martyn Stone said: “We were so impressed with little Olivia’s incredible efforts in fundraising for the A-T Society, we’ve decided to match her fundraising total, taking it up to £874.

“We’re also awarding her our Pentagon Golden Heart Award.

“Plus, we’re giving Olivia a brand new ZOGGS swimming costume and goggles since we understand that it is something that she would really like. This kind of altruism from someone so young deserves to be rewarded.”

Olivia, who has been swimming since she was three months old, said of her challenge: “I was a little light-headed at the end, and was very hungry, but it was fun.”

Ataxia-telangiectasia is a complex disorder which affects different systems within the body, including difficulty in controlling movements and reduced efficiency of the immune system, leading to more frequent infections.

Suzanna Roynon, A-T Society fundraiser, said: “A-T is a diagnosis which parents dread, and with six people living with the condition in Medway alone, we know it is hiding in the local gene pool and that anyone in the area could be a carrier.

“This extraordinary young girl has shown compassion and humanity, and it’s clear these values will have been instilled both at school and at her home.

“For a six-year-old to take on a swim twice that of an Olympic triathlon event is something we have never seen before. We cannot thank her enough.”