Twitter co-founder and chief executive Jack Dorsey’s account was hacked on Friday, and used to post a series of erratic and offensive messages.
A group referring to itself as the Chuckling Squad said it was behind the breach of Jack Dorsey’s account.
A spokeswoman for Twitter told the BBC that the site was urgently investigating.
The news comes with Dorsey and Twitter moving aggressively to clean up offensive and inappropriate content as part of a focus on “safety.”
The account, which has more than four million followers, tweeted out a flurry of highly offensive and racist remarks for about 15 minutes.