Retired boxer Mike Tyson was professionally hypnotised before his fights to ensure he was as ferocious as possible in the ring.

Tyson won his first 19 fights by knockout after becoming a professional boxer aged 18 and he developed a reputation for being a particularly vicious and aggressive fighter, who would quickly charge down opponents at the opening of the first round.

The troubled sports icon now attributes the ferocity of his fights to a hypnotist, who he worked with several times a day at the request of his manager Cus D'Amato.

He tells Britain's Daily Telegraph, "Cus used to have me professionally hypnotised two or three times a day - before sparring, before training and before fights. My objective was to destroy."

When asked if he ever felt remorseful about the viciousness with which he attacked his opponents, Tyson replies, "No, because Cus didn't like me to be sensitive like that. He wanted me to be emotionless. He said feelings mean nothing. Feelings have nothing to do with your life. The only thing feelings do is distract you."