A photo, submitted to this newspaper at 6.20pm, showed the vehicles on the Downs Leisure Centre pitch on Sutton Road.
The image also showed a pony at the site.
A spokesperson from Wave Active, which operates the leisure centre, said on Wednesday, August 5: “We can confirm that the matter was resolved within three hours.”
East Sussex County Council said the encampment is no longer there and the vehicles left late on Tuesday night.
A Sussex Police spokesperson said: “Officers responded to reports of an unauthorised encampment at this location on Tuesday 4 August. An enforcement notice was served and all vehicles left the location the same evening.
“Anyone with any information relating to any criminal activity can report it online or call 101, quoting serial 1321 of 04/08.”
1. Downs Leisure Centre
Caravans and campervans on a football pitch at Downs Leisure Centre in Seaford on Tuesday, August 4. Photo: Sussex News and Pictures Photo: Sussex News and Pictures