An eight-year-old boy had a “really special” day meeting the Duke and Duchess of Cambridge – just after he had finished his cancer treatment.

Otto Warner completed his six months of chemotherapy on Tuesday before meeting the royal couple with his sisters Poppy, 10, and Jasmine, 5, along with his grandparents Dickie and Annie and mother Georgie at Bath Spa train station.

Mrs Warner, 43, said Kate and William were “really kind” and put her children “at ease right away” just hours after Otto rang the bell signalling the end of his treatment at the starlight ward in Bristol Royal Hospital for Children.

Mrs Warner, from Bath, told the PA news agency: “It was just really lucky and wonderful that we were there and could meet them. We had no idea that was going to happen.

“It was really, really special. They were so kind and made a huge effort to speak to them and encourage them.

“They are so natural talking to children and put them at ease right away.

“We were delighted to ring the bell with all the nurses this morning, it was so emotional.

“We got in the car and this is the next thing that happened for Otto – and it came on the day of the first vaccines as well.”

For six months Otto had five days of chemotherapy every three weeks to treat his anaplastic large cell lymphoma (ALCL) which was spotted early by his grandfather Dickie Maw, 80, a retired medic.

Mrs Warner went on: “Otto was in a lot of pain at night with tummy aches and my father knew something wasn’t right.

“We’re very lucky it was caught early and my dad saved his grandson’s life.”

She paid tribute to the doctors and nurses on the starlight ward of the hospital, adding: “They gave us the most amazing and phenomenal treatment, we can’t thank them enough.

“My heart goes out to the other children and the other parents in there, I pray for all the other children.”