Dozens of people are suffering from Norovirus-like symptoms after attending a huge Lego event in Bristol over the weekend.
Organizers of the Bristol Brick show say they are "devastated" and are launching an investigation by the city's health authorities.
Nearly 4,000 people visited the Indoor Action Center to celebrate Lego, but after the event, more than 40 in attendance began to experience illness and diarrhea.
One Lego fan, who wants to remain anonymous, said he was unhappy with the cleanliness of the place.
He said: "The condition of the site left much to be desired."
"The food was not great and at the weekend, the toilets were not well maintained, the basins were not working well and there was no hand sanitizer and that kind of thing."
"At least 40 people I know are affected."
The Bristol Brick show posted a post on its Facebook page Wednesday afternoon saying: "Thank you all for coming to our show, enjoying it and helping us raise money for two very worthy charities.
"We are aware that a large number of people attending our weekend event have since been affected by the virus.
"Unfortunately, there were no reports of illness made during the show's duration, so we had no way to warn anyone or identify a source at the time.
"Many of you will know that Bristol has recently seen more cases of Norovirus affecting schools, hospitals and other business activities in the area and a combination of that plus nearly 4,000 people through our doors over the weekend seems to have contributed to the outbreak.
"We stayed at the same event last year with no known topics, so we are confident that this is an unfortunate and isolated incident.
"As organizers, we are devastated that this has put the damper on an otherwise successful show, obviously we wish everyone who is affected by the rapid recovery.
"Thank you for your continued support and we hope your memories of the show are not marred by these events!"