LONDON — Britain's Rupert Murdoch-owned tabloid The Sun has sent a message to readers warning them that computer hackers may have published their data online after an attack on the paper's website last month.

The paper's publisher News Group Newspapers (NGN) said in an email late Monday that details of people who took part in competitions and polls on The Sun's website may have been taken.

NGN, which is part of News International and published the Sunday tabloid News of the World until its closure amid a phone hacking scandal last month, said names, addresses and phone numbers may have been published. It said no financial or password information was affected.

Hacking group LulzSec claimed responsibility for the cyber attack, which forced Murdoch's British papers to pull their websites and culminated in The Sun's site being replaced with a hoax story reporting the mogul had died.

"As you may be aware, on July 19 the Sun website was subject to an organised criminal attack," said the email to Sun readers sent out by Chris Duncan, director of customer management at News International.

"It has now come to our attention that some customer information from competitions and polls was breached as part of this attack.

"Details vary, but could include name, address, date of birth, email and phone numbers. No financial or password information was compromised.

"We are contacting you because we believe that information that you submitted to us could have been accessed, and may be published online by the group responsible."

Duncan added the company was working with police and the government's data protection watchdog to try to retrieve the stolen data.

LulzSec has claimed responsibility for a 50-day rampage earlier this year against international businesses and government agencies, including the Central Intelligence Agency and Senate in the United States and electronics giant Sony.

On Monday, an 18-year-old suspected of being a spokesman for LulzSec and another hacking group Anonymous was granted bail at a London court after being charged with hacking into websites.