Microsoft Corp worked closely with U.S. intelligence services to help them intercept users' communications, including letting the National Security Agency circumvent email encryption, the Guardian reported on Thursday.
Citing top-secret documents provided by former U.S. spy contractor Edward Snowden, the UK newspaper said Microsoft worked with the Federal Bureau of Investigations and the NSA to ease access via Prism - an intelligence-gathering program uncovered by the Guardian last month - to cloud storage service SkyDrive.
Microsoft also helped the Prism program collect video and audio of conversations conducted via Skype, Microsoft's online chat service, the newspaper added.
Microsoft had previously said it did not provide the NSA direct access to users' information. On Thursday, it repeated that it provides customer data only in response to lawful government requests.
"To be clear, Microsoft does not provide any government with blanket or direct access to SkyDrive, Outlook.com, Skype or any Microsoft product," the company said in a statement on its website.
Facebook Inc, Google Inc and Microsoft had all publicly urged U.S. authorities to allow them to reveal the number and scope of the surveillance requests after documents leaked to the Washington Post and the Guardian suggested they had given the government "direct access" to their computers as part of the NSA's Prism program.
The disclosures have triggered widespread concern and congressional hearings about the scope and extent of the information-gathering.
© 2015 Thomson/Reuters. All rights reserved.