Butlin’s has set up a dedicated team to contact customers who may have been affected by a data hack.
The UK seaside holiday parks operator said up to 34,000 guest records may have been accessed.
It says names, home addresses, email addresses and telephone numbers have been accessed, but it insists financial data has not been compromised.
Butlin’s managing director Dermot King said: "Butlin’s take the security of our guest data very seriously and have improved a number of our security processes.
"I would like to apologise for any upset or inconvenience this incident might cause.
"A dedicated team has been set up to contact all guests who may be affected directly.
"I would like to personally reassure guests that no financial data has been compromised."
Butlin’s has reported the incident to the Information Commissioner’s Office.
