Legoland closed its Windsor resort hotel over the weekend amid security scares.
The company said threats were made to staff and visitors over a Muslim family fun day that was due to be held at the theme park.
More than 4,000 people were expected to attend the private event organised by the Muslim Research and Development Foundation (MRDF), according to Sky News.
A Legoland spokeswoman said the park had been contacted by a number of right wing groups "relentlessly and aggressively online and via the telephone".
She told Sky News: "The safety and security of our guests and our members of staff has to be our number one priority, which is why we’ve made the difficult decision to close the hotel."
Offensive blogs and images also appeared on social media.
The Berkshire theme park itself is due to reopen to the public for the 2014 season on March 14.
Thames Valley Police is investigating.
