Twitter investigates celebrities' missing tweets
Twitter says it is investigating a bug that has caused some messages to become unavailable on its service.
Accounts affected include those belonging to the singers Lady Gaga, Justin Bieber and One Direction's Louis Tomlinson.
Oscars presenter Ellen DeGeneres's selfie from the Academy Awards - the most retweeted picture of all time - was also affected.
Several, but not all, of the messages have now been restored.
Attempts to click on links to the missing tweets bring up a message saying: "Sorry, that page doesn't exist!".
"We are currently researching a bug that has caused some Tweets to not be displayed," the service tweeted on its status page on Tuesday evening.
The account indicated this was the third time the US company had experienced a significant fault this month.
Previous problems involved a 45-minute period when many users were unable to log in to the service after a botched upgrade that was later "rolled back", and a 25-minute period when some users were unable to send or receive tweets from mobile apps.
The current fault appears to have lasted for more than 12 hours.
Among the tweets that became inaccessible were:
- a photo posted by the US singer Lady Gaga showing her alongside Miley Cyrus, with the caption: "Do not leave your children with Lady Gaga," from September 2013
- a message posted by Canadian singer Justin Bieber to mark the death one of his fans saying: "RIP Avalanna. I love you," from September 2012
- a post from One Direction's Louis Tomlinson to his bandmate Harry Styles saying: "Always in my heart @Harry_Styles. Yours sincerely, Louis," from October 2011
It was reported that several of Styles's own tweets had also disappeared.
Several Twitter users also complained he last message posted by the actor Cory Monteith had also become inaccessible. The Canadian star of Glee died in July from a heroin overdose.
His message is among the posts that have since been restored.