Mr. Roberts was a Muggle man who managed the campsite near to where the Quidditch World Cup was held in 1994. He lived with his wife and two children in a stone cottage at the front of the campground. His youngest child was a boy.
Mr. Roberts believed that his wizarding guests were confused with Muggle money because they were all from out of the country. Ministry of Magic employees were required to perform Memory Charms on him several times a day.
When Arthur Weasley and his party were leaving the campsite the following morning, Mr. Roberts wished them a Merry Christmas, although it was the middle of summer. Mr. Weasley explained that Mr. Roberts had been left temporarily disoriented by the Memory Charm that had been used to erase his memories of the Death Eater attack.