JK Rowling helped Kate McCann to write her book on missing daughter Madeleine.

The Harry Potter author gave advice as she penned details of the youngster's 2007 disappearance in Portugal.

Kate hopes to raise £1million from the book.

She said: "Every penny will go on the search for Madeleine."

WITH cash draining from the fund set up to hunt for Madeleine McCann, JK Rowling’s pledge to help was a welcome boost to mum Kate.

The Harry Potter author gave the devastated 42-year-old advice and support as she wrote the harrowing details of the night her daughter vanished from their holiday apartment on the Algarve.

Kate’s book is expected to raise £1million and she and husband Gerry, both 42, hope it will help shed new light on how Madeleine vanished four years ago.

Rowling, 45, is a supporter of the Madeleine Fund, which has ­dwindled to £200,000.

TRUTH

The book, called Madeleine, will be published on May 12, the ­youngster’s eighth birthday. The money it raises should be enough to pay for private detectives to keep working on the case that gripped the world for another two years

Kate, of Rothley, Leics, said: “My reason for writing is simple, to give an account of the truth.

“Publishing this book has been a very difficult ­decision and is one that we have taken after much ­deliberation and with a very heavy heart.

“However, with the depletion of Madeleine’s fund, the decision has been taken out of our hands. Every penny we raise through its sales will be spent on our search for Madeleine. Nothing is more important to us than finding our little girl.”

Gerry added: “We are hopeful this book may help the ­investigation to find Madeleine.

“Our hope is that the book may prompt those who have relevant information to come forward and share it. Somebody holds that key piece of the jigsaw.”

Rowling has been heavily involved in the search for Madeleine since she vanished in May 2007. The writer offered a reported £1million reward to find the youngster.

She also donated to the fund set up to aid the worldwide search. Rowling arranged for a poster featuring Madeleine to be made available to book retailers across the globe.

And last November she helped Kate and Gerry to secure their book deal. She suggested they use her literary agent ­Christopher Little, who arranged a publishing contract with Transworld.

Last January, Rowling met the couple, both doctors, at a fund-raising event in London to mark the 1,000th day since Madeleine vanished from Praia da Luz.

Her official website features a Madeleine section giving details of her case and phone numbers to contact with information.

PRIEST

Since the youngster disappeared on May 3, 2007, aged three, Kate, also mum to six-year-old twins Sean and Amelie, has made a number of secret trips back to the resort.

She goes alone and stays with Haynes Hubbard, the local Anglican priest and his wife Susan.

Father Hubbard said: “She doesn’t enjoy being in front of the camera but she is prepared to do it because it might bring her child back.

“They need money to carry on the investigation. They will never stop looking and that’s why this book has been written.

“It probably tears them apart to do this but the child is worth it.”

Friends say Kate will “want to settle some scores” – particularly with the Portuguese police, who investigated the disappearance and became convinced, wrongly, the child’s parents were involved.

After numerous false hopes in the search the book may be one last throw of the dice for the family.