Twitter CEO Jack Dorsey has had his own account on the platform hacked.
Several racist posts were sent from the @Jack account, which has more than four million followers.
Twitter posted an update that said: "We're aware that @jack was compromised and investigating what happened."
The offending tweets have since been deleted.
Mr Dorsey, 42, is a co-founder as well as CEO of the platform.
He is also the founder and CEO of Square.
Twitter has been awash with comments regarding Mr Dorsey's hack in the wake of the tweets.
One person wrote: "If @jack can get hacked, twitter safety is a joke."
