Web hosting firm 123-reg was hit by a technical fault that resulted in the company accidentally deleting virtual servers and websites.
According to the company, which hosts 1.7m sites in the UK, an error during maintenance effectively deleted the content of some of its servers.
The company said: "We can conclude that the issues faced have resulted in some data loss for some customers."
A small proportion of the web hosts websites have been deleted due to a piece of faulty code, according to one of its customers Innmaster, a cloud software provider.
The company said in a blog post: "At 7am on Saturday morning, someone at our hosting provider ran a script that had a catastrophic error in it. The result was that the script deleted the servers and websites of all their customers!"
No comment has been made by the company as to the specific behind what caused the disruption or whether the 123-reg keeps a backup copy of its customers’ data.
The company said: "Many of our customers keep their own backups. We are currently working with a team of experts on data recovery."
The web hosting company, which has 800,000 customers in the UK, said in an email to customers that it has begun copying recovered virtual private servers (VPS) images to new hosts and that some websites should expect to be restored overnight.
In addition to this the company is planning to audit all of its automated scripts and prevent customer websites from being deleted without human approval in the future.
The error first occurred on Saturday morning during routine maintenance which saw it run a script that was intended to indicate virtual server activity. In error, the script shows some VPSs as running no servers and automatically deleted what was running on the host, said Richard Winslow, 123-reg brand director.
