An “incredibly brave” six-year-old girl battling a rare and aggressive type of cancer has died.

Kaiya Patel stole the hearts of many after her parents began campaigning to find a stem cell donor for her when she was diagnosed with Acute Lymphoblastic Leukaemia at Watford General Hospital on March 28, 2018.

The smiley St. Helens schoolgirl from Loudwater died late on Sunday evening from an adenovirus she contracted following a recent transplant.

Her parents, Anu and Ruchit, published a touching tribute to their daughter on Facebook on Monday, describing her as their “Angel Kaiya” and praising her “determination and willpower”.

Their tribute, which appeared on “Be Kaiya’s Donor” at around 8pm that evening, received well over 4,000 comments and messages of condolence - many expressing deepest sorrow at the news; others praising Kaiya for her courage and “beautiful” personality.

Anu and Ruchit said hers was not “a life led with no meaning” and that the donor drive her condition inspired had already helped “many children with cancer”.

In addition, they said her campaign had “brought about a change in a drug protocol that means other kids with adenovirus will not suffer the same fate as her”.

They said she was “loved by all”.

Kaiya enjoyed running, gymnastics and ballet. Last year in November, she was awarded the John Petchey Young Hero Award at the Anthony Nolan Supporter Awards.

In August, her family found out a donor had been found and in September she received her stem cell transplant.

Since her diagnosis in March last year, her parents have been actively encouraging people to approach blood cancer charities Anthony Nolan and DKMS to request a donor application form.

Anthony Nolan’s chief executive, Henny Braund, made the following tribute to Kaiya: “We are all deeply saddened to hear the news that Kaiya, whose family set up the ‘Cure Kaiya’ campaign, passed away on Sunday. Her death at such a young age is simply a tragedy.

“Kaiya’s inspiring family and their incredible work signing up thousands of potential stem cell donors from diverse backgrounds, has created a lifesaving legacy in Kaiya’s name, that will continue to give people a second chance of life for many years to come.

“We hope this is of some comfort to all who knew and loved her, and our thoughts are with Kaiya’s family at this difficult time.”

Kaiya is survived by her mother and father, Anu and Ruchit, and little sister Annika.