Nestle has been forced to apologise after joking about the disappearance in Mexico of 43 trainee teachers, whose abduction and probable murder has outraged the nation.
The students were abducted on September 26 by police thought to be working in collusion with drugs cartels. They have not yet been found, but on Friday the attorney general, Jesus Murillo Karam, gave a press conference in which he said that three cartel members had confessed to shooting the students in a rubbish dump, then burning their bodies.
But just after midnight on Sunday, a tweet published by a Mexican account dedicated to Nestle's "Crunch" brand chocolate bar, said: "A los de Ayotzinapa les dieron Crunch" - a pun on a slang Mexican expression, which translates as: "They crushed those from Ayotzinapa".
A spokesman for Nestle Mexico said on Monday that the tweet was removed shortly after publication, and that it was "unauthorised".
She said the company had initiated an investigation to find out who had sent the tweet but would not to say whether the account had been hacked.
On Monday, the company issued a fresh tweet that read: "Once more we offer the sincerest apology for this offensive tweet which is completely contrary to our values."
The company has since published a stream of apologies to angry Twitter users.
"We share your concern, and that of the public. This message was totally contrary to our values," they wrote on Monday night.