It was a tweet that insulted a rescuer, who played a leading role in saving a group of boys trapped in a cave in Thailand.. and now Elon Musk has said sorry to Vern Unsworth..

Tweeting: "His actions against me do not justify my actions against him, and for that I apologize".

Unsworth, had criticized Musk in an interview, saying the Tesla CEO's offer of a submarine for the rescue operation had "no chance of working" and that he should stick the submarine "where it hurts." That prompted Musk to respond, calling Unsworth a pedophile.

Musk's post was later deleted.

Shares in Tesla fell 3.5 percent on Monday after his tweets Investors have told Reuters Musk's his comments added to concerns he's being distracted from Tesla's main business of producing electric cars Tesla has struggled to meet its production targets for its Model 3 Sedan, which is seen as key to the company's profitability Unsworth is returning to Britain on July 19 and is seeking legal advice.