Big steel gates have disappeared in an audacious theft from the entrance to a Neudorf property.

Owner Carol Martin is dismayed and incredulous at the theft which was discovered on Christmas morning.

"It's unbelievable and it's disgusting," she said. "We're still reeling and can't believe people would do that."

The family heard nothing on Christmas Eve when the heavy 1.8-metre high gates were lifted off their gudgeons.

"It must have been planned. One person could not lift them on their own. They would not fit on a ute, they would have needed a flat deck truck or trailer."

The maroon gates with a diamond design are a one-off, made six years ago, and would cost about $4000 to replace.

Usually they would be open and not noticeable but recently they had been closed because of sheep on the property.

The family also breeds show ponies so needs the gates to keep the mares and foals safe when being moved.

Mrs Martin said someone might have the big steel gates not realising they had been stolen.

"We're not sure what has happened, only that they are gone."

The family home is 250m from the gates and their daughter's place is 100m away, but no-one heard the gates being removed.

"It's shattered our Christmas, we can't believe there are such low-lifes out there," Mrs Martin said.

They have reported the theft. Anyone with information can call the police on 03 546 3840. The reference is 131225-5598.