River Dart Country Park has been closed until next Monday as officials investigate the suspected outbreak of a noro-type virus.
Since Friday more than 90 people at the holiday park near Ashburton have reported similar symptoms of sickness and diarrhoea.
Now the company has sent 600 people home and apologised for the disruption caused.
The pirate ship lake at the holiday park near Ashburton has been drained and closed while the source of the sickness bug is investigated by health officials.
Samples and specimens were passed to South Hams District Council Environmental Health department, with results expected in a day's time.
Posting on the company's Facebook page, Managing Director Mark Simpson said: "Following discussions with the Environmental Health Agency and Public Health England, the Management Team and I have jointly taken the decision to close River Dart Country Park until August 18 2014.
"This will enable further investigation into the suspected Noro-type virus, which was unwittingly brought on to our site, to continue and a deep clean of the whole site be undertaken.
"Our primary concern is naturally for the welfare of our visitors and we have not taken this very difficult decision without serious consideration.
"I fully appreciate that this will cause unforeseen disruption to many holiday and day visitor plans for which I can only apologise."
The Norovirus, described by the NHS Choices website as "the most common stomach bug in the UK", usually leads to mild diarrhea, vomiting and abdominal or stomach cramps.
Dr Sarah Harrison, Interim Deputy Director of Health Protection for the Devon, Cornwall and Somerset Public Health England Centre said: “The virus is highly contagious. It can affect people of all ages and causes vomiting and diarrhoea.
“There's no specific cure for Norovirus, so you have to let it run its course. It's usually mild and shouldn't last more than a couple of days.
“Although having Norovirus can be unpleasant, it's not usually dangerous and most people make a full recovery within a couple of days without having to see their GP.”