Fans were sent into a state of confusion when a series of tweets issued by Jack Black's band, Tenacious D, announced that the star had died.
The official Twitter account for the comedy band - made up of Black and musical partner Kyle Gass - tweeted that they are "sad to officially annouce (sic) the death of Jack Black at the age of 46, rest in peace brother."
A second tweet an hour later sent out the hashtag #RIPJackBlack, while a third read, "It is with a heavy heart I am to announce that Jack Black passed away last night at 3.37am. The cause of death is yet unknown."
The announcement shocked fans - but many wondered if it could be a Twitter hack, given the lack of detail, spelling and grammar errors and absence of other credible reports.
And it appears they are right. The hacking was later confirmed by Tenacious D themselves, who said it was nothing but a "sick prank".
John Konesky, a guitar player with Tenacious D, also confirmed the tweets were the result of hacking.
Other tweets pointed to Twitter account @Ruthless, which appears to have gained control of the Tenacious D account.
"RT if I fooled you all!" @Ruthless tweeted, which was quickly retweeted by Tenacious D.
Tenacious D is just the latest in a string of high-profile Twitter hacks - only days ago, Katy Perry's Twitter account was hacked, with the responsible issuing offensive tweets from her account and accessing unreleased music she had been recording.
There seems to be an explanation as to why they haven't yet been deleted: Tenacious D are touring Europe at the moment, and several fans have tweeted that they met Black at an airport in Germany earlier today before he boarded a flight to the US.
Tenacious D's official Facebook page has been flooded with fans asking for confirmation of the news - as yet, the band have not posted on Facebook about the 'death'.
Black's own official Facebook page has not posted an update since May 20.
According to Tenacious D's social channels, Black was indeed alive and well performing in Europe last night.
And one Twitter user pointed out that Black had been pictured on DJ Diplo's Snapchat just eight hours ago.