AWARD-WINNING cartoonist and illustrator Bill Leak was seriously injured in an accident on ad man John Singleton's Central Coast property yesterday afternoon.

Mr Leak was taken to Royal North Shore Hospital by helicopter after the accident in which he reportedly fell from a veranda at Mr Singleton's Strawberry Hill Stud at Mount White.

A strapper who works at the stud told a friend of Mr Leak that paramedics arrived on the scene and immobilised him before putting him in the helicopter.

A spokeswoman for Royal North Shore Hospital said Mr Leak, who lives on the Central Coast at Hardys Bay, arrived at the emergency department in a serious condition last night.

He was undergoing tests, including a CAT scan, to check for spinal problems and other internal injuries.

"He is undergoing preliminary tests to find out the exact extent of his injuries, but at the moment his condition is serious," the spokeswoman said.

Mr Leak, 52, is a cartoonist at The Australian newspaper and has won two Walkley Awards for his work.

He is also a well-respected portrait painter and has entered the Archibald Prize 13 times. He has won the Packing Room Prize twice and also won the People's Choice award for a portrait of Malcolm Turnbull.