Initial reports indicated that the leak occurred due to a breach in Apple's iCloud, prompting Apple to take swift investigatory action.
"When we learned of the theft, we were outraged and immediately mobilized Apple's engineers to discover the source," Apple said in a statement. "Our customers' privacy and security are of utmost importance to us."
Apple's investigation concluded the celebrities' accounts were accessed after individuals were hit by "phishing" scams, where criminals obtain usernames and passwords by pretending to be a recovery service for a more official program.
"After more than 40 hours of investigation, we have discovered that certain celebrity accounts were compromised by a very targeted attack on user names, passwords and security questions, a practice that has become all too common on the Internet. None of the cases we have investigated has resulted from any breach in any of Apple's systems including iCloud or Find my iPhone. We are continuing to work with law enforcement to help identify the criminals involved."