Twitter's most retweeted tweet of all-time vanished from the platform on Tuesday for more than five hours.
The curious case of the vanishing tweets came to light when users of the social media service began buzzing late afternoon that tweets were mysteriously disappearing.
Tweets that vanished included actor Cory Monteith's last tweet before his death, Ellen DeGeneres' viral selfie—which racked up more than 3.4 million retweets at one point—and a breaking news post from @CNBC. Editors at various media companies also said they noticed posts had vanished.
(Read more: Facebook buying virtual reality firm Oculus for $2 billion)
"At least I got the tweet framed before it got deleted," a fan of Justin Bieber posted along with a frame showcasing a tweet that could no longer be found on the singer's profile.
For nearly a day, Twitter said it researched a bug that caused tweets not to display. After more than 20 hours of exploration, Twitter took to its status blog to say the "issue has been resolved, and affected Tweets, along with the favorites and retweets on those Tweets, have been restored."
When asked what exactly caused famous tweets to temporarily not display and what it plans to do to prevent the issue from happening again, Twitter would only tell CNBC that "it was a bug."
Twitter's hiccups came as Facebook announced its $2 billion acquisition of virtual tech firm Oculus and as Instagram said it now has more than 200 million monthly active users. In total, Facebook now has 1 billion monthly active users of its apps, while Twitter's mobile app is utilized by 184 million users each month.
—By @CNBC's Eli Langer. Follow him on Twitter at @EliLanger. CNBC's Steve Kopack contributed to this story. Follow Steve on Twitter at @SteveKopack.