AUTHOR J.K. Rowling has been flexing her muscles in the literary world.

The Harry Potter scribe has reportedly helped Kate and Gerry McCann to secure their book deal.

Rowling — who has been giving the McCanns support since their daughter disappeared in Portugal in May 2007 aged three — suggested the couple use her literary agent Christopher Little who arranged a publishing deal with Transworld, according to Britain’s Daily Express newspaper.

Rowling contributed to a reward for finding Madeleine and in July 2007 she arranged for posters of Madeleine to be made available to book retailers around the world.

The book — titled Madeleine — will be published on April 28 next year to mark the fourth anniversary of her disappearance. Profits will go directly to the fund for finding Madeleine.

Kate has already written 60,000 words, covering the period up to the couple’s heart-rending decision to return to Britain.

“My main reason for writing is simple — to give an account of the truth,” Kate said.

Rowling recently hinted that she might write another Potter book.

“I could definitely write an eighth, ninth, tenth,” she said.

“I’m not going to say I won’t. I don’t think I will … I feel I am done, but you never know.”

Rowling said she felt something of a loss upon finishing the saga’s last installment, Harry Potter and the Deathly Hallows. “It was a bereavement,” she said.

Rowling says she plans to write more books away from Potter — and feels there is no need to match or top her previous achievement.

“I did it. I’m really proud I did it,” she said. “But this is a new phase.”