Farmer Tim Carson is rethinking his policy on allowing people to visit crop circles in his fields after his honesty box was trashed last week.
Mr Carson, who farms at Alton Barnes, regularly has formations appear in the field below the Alton Barnes white horse.
The money box put out for visitors to make contributions was raided while he was on holiday last week.
He said: “This has left a sour taste. It must have been someone local who knew I was away and wasn’t emptying the box every evening.
“I wouldn’t like to think it was a visitor. They are always polite and considerate.”
The box, a converted tool box welded to a 40-gallon drum, was in the middle of the field close to the circle. It had been forced open.
Mr Carson said: “I’ve no idea how much was in the box. This has really cheesed me off. I would hate to do what other farmers do and mow out the circles before anyone can visit them, but I may be forced to after this.”
The complex seven-sided figure appeared in the field below Milk Hill at the beginning of June. A simpler design turned up in East Field, where Mr Carson also farms.
It was in one of his fields that the first “pictogram” design of crop circle appeared in 1991, sparking an international fascination with the formations.
Mr Carson has always been sceptical about their origins, but has had a “live and let live” attitude to investigators.
Others are not so tolerant. A 62-year-old man from Oldham was arrested after it was alleged shots were fired over the heads of two Norwegian tourists visiting a circle at Manor Farm, Allington, on July 13. He must report back to police in August.
Anyone with information about Mr Carson’s theft is asked to contact Wiltshire police on 0845 408 7000.