During his teenage years, McLean mixed with various local criminals. He was arrested for petty crimes and served 18 months in prison. After he was fired from his first legitimate job for beating up his
foreman, he worked odd jobs. By the age of fifteen, McLean realised he could earn a living from fighting and pursued it as his main means of income. McLean's first unlicensed boxing match came about as a result of a chance meeting while in his late teens. When his car broke down in the
Blackwall Tunnel, he abandoned it and went to buy a replacement from an associate named Kenny Mac, a
gypsy used-car salesman in Kingsland Road,
Hackney, only to find the replacement quickly failed too. McLean returned later to demand his money back. Instead of refunding McLean, Mac offered to give McLean a new car in exchange for him fighting in one of Mac's unlicensed boxing bouts later that night in Mac's yard. McLean's opponent lasted less than a minute against him, earning McLean £500, a considerable prize at the time. Mac and McLean became friends and on numerous later bouts Mac acted as McLean's boxing manager. McLean became the best-known bare-knuckle street fighter in Britain. When
Frank Warren formed the National Boxing Council in the 1970s, it allowed the toughest underground fighters in Britain to compete legally. McLean, unable to become a licensed boxer due to his violent reputation and lengthy criminal record, entered the world of unlicensed boxing, which, although legal, was not sanctioned by the
British Boxing Board of Control. He quickly became one of its brightest stars and had a fearsome reputation. McLean had a famous trilogy of unlicensed matches with arch-rival
Roy "Pretty Boy" Shaw. McLean lost to Shaw once via verbal submission, which McLean justified by claiming his gloves had been tampered with, reducing their maneuverability. McLean beat Shaw in a rematch with a dramatic first-round
knockout, in which Shaw was physically knocked out of the ring. In their final bout, McLean ended the feud with a brutal first-round knockout at the
Rainbow Theatre in
Finsbury Park, London in September 1978. McLean, who in his prime was tall and weighed over , boasted that he could beat anybody, in either a legitimate match or in an unlicensed match with or without gloves. He reputedly sent out challenges to many of the famous boxers of the day, including
Muhammad Ali and
Mr. T, though neither contest materialised. McLean lost some
face as he was challenged by the "King of the Gypsies"
Bartley Gorman, but did not accept the fight. He was offered a fight with professional boxer
David "Bomber" Pearce, the hard-hitting British heavyweight champion from
Newport. McLean declined to fight Pearce; he later commented that was the only time in his career he had doubts. Large portions of McLean's career cannot be verified, since his fights were unsanctioned by the boxing authorities. He was known to have lost several fights, although he always maintained that he had never lost a fight "on the
cobbles" or outside the ring. In unlicensed matches, he was twice stopped by Cliff Field. Field had been beaten by Pearce's brother, 'Bimbo Pearce', and twice beaten by Johnny "Big Bad" Waldron. McLean also lost via KO to George "Pappy" Langley and on points to Kevin Paddock. In his autobiography, McLean claimed to have competed in almost 4,000 fights over three decades, and said he won the large majority of these. ==Other professions==