The UK government accidentally published the addresses of recipients of the 2020 New Year's honours.
The list included addresses of performers, politicians, scholars, doctors, chief executives, and government officials.
"A version of the New Year Honours 2020 list was published in error which contained recipients' addresses. The information was removed as soon as possible," a Cabinet Office spokesperson said in a statement.
"We apologise to all those affected and are looking into how this happened."
The Cabinet Office referred the incident to the Information Commissioner's Office - the UK's independent authority on data protection.
The document, which British media said contained over 1,000 addresses, went online late Friday night before being taken down within an hour.
Among those whose addresses were on the list include singer Sir Elton John, historian Sir Keith Thomas, Conservative MP Iain Duncan Smith, entertainer Olivia Newton-John, and Labour MP Diana Johnson.
Sir Elton John and Sir Keith Thomas were both awarded Companion of Honour awards, the highest accolade on the list.