J.K. Rowling is to build an equestrian centre at her mansion

The 51-year-old writer's husband is listed as the director of the build, according an application by horsing company Blagdon Equestrian Limited obtained by The Sun newspaper.

The design plans state: "The farmland is mixed grazing, arable and there is a group of farm buildings and dwellings. The applicant acquired the farm in 2012 by which time the property had fallen into a state of disrepair.

"All the buildings had suffered from lack of maintenance and field fences and walls were broken down.

"Woodland areas were badly overgrown and dangerous, field drainage had failed and outbreaks of Japanese Knotweed were discovered. The new owners embarked on a programme of improvements designed to secure a viable future for the farm."

However, a representative for the star - who is believed to be worth around £600 million - is yet to comment.

Earlier this year, Rowling - who has been married to Neil since 2001 - splashed out on Hollywood actor Johnny Depp's yacht.

The 51-year-old writer put £22 million down to secure the sale of the luxury 156-foot vessel as she was fascinated by its five cabins and three large decks after she took it out on a family charter trip.

Rowling intends to spend holidays on the boat with her husband and their two children David, 13, and Mackenzie, 11, as well as her 23-year-old daughter Jessica from a previous relationship.