Tyson Furys reign as world heavyweight champion could be nearing a sad end following recent revelations about his cocaine use, and a second failed drug test.Fury has not been able to defend his titles since taking them off Wladimir Klitschko last November, and risks losing his licence, as his private life has spiralled in the aftermath of what should have been the greatest night of his life.The British boxer clearly has personal problems that he must come to terms with and address, but does he have a future in the ring? ESPN looks at five previous champions, and their battles, to find an answer.Sugar Ray LeonardConsidered one of the greatest fighters ever to step inside a ring, Leonard has admitted battling with a cocaine addiction during the 1980s. Having originally called time on his career in 1982, following an eye injury, the five-weight world champion turned to the drug to combat anxiety.Leonard would fight just once in the next five years -- a knockout of Kevin Howard in 1984 -- as his addiction took hold. However, he was able to beat his demons and following a split decision win over Marvin Hagler, would remain in the sport for another decade, winning titles at middleweight and super middleweight.Leon SpinksSpinks made history when he beat Muhammad Ali on Feb. 15, 1978. In just his eighth professional fight, the then-24-year-old had become world champion -- no one had ever done it quicker. His success should have signalled the start of a long and illustrious career.Unfortunately for Spinks, the demons that would derail his career were already bubbling close to the surface. Just two months after his defeat of Ali, the American boxer was arrested in possession of cocaine and marijuana. He would fight until the age of 42, but he was never able to fulfil the promise of that first world title fight, losing the rematch to Ali before being knocked out by Larry Holmes in 1981.Sirimongkol SingwangchaThai boxer Singwangcha won world titles at bantamweight and super featherweight in the 1990s and 2000s, before being arrested in possession of drugs in his homeland in 2009. He was sentenced to 20 years in prison, but served only four due to his status as one of his countrys biggest boxing talents.Singwangcha continued to fight following his release and remains active, having gone more than 10 years without defeat.Oliver McCallMcCall stunned Lennox Lewis to win the WBC heavyweight title at Wembley Arena in 1994, a crown he would lose to Frank Bruno next door at Wembley Stadium 12 months later. The Americans battle with addiction became painfully obvious to those watching in Las Vegas in 1997 as he began to weep as he lost his rematch with Lewis.His career was marked by a number of run-ins with police and stints in rehab, culminating in two arrests in 2010 for drug possession. McCall was declared alcohol and drug-free for 2011, and continued fighting until 2014.Ricky HattonHatton came to prominence with a stunning victory over Kostya Tszyu in 2005. The Mancunian followed that up with wins over Luis Collazo and Jose Luis Castillo.However, his diet outside of the ring had long been a cause for concern and heavy defeats to Floyd Mayweather Jr. and Manny Pacquiao pushed him towards retirement. Just over a year after his loss to Pacquiao a newspaper sting alleged Hatton was a regular cocaine user. Hatton made one final, losing appearance in a boxing ring before concentrating on his promoting work. Jordan 13 For Sale Cheap . The 18-year-old American had five birdies in her bogey-free round for a 17-under total of 196. Lee held the overnight lead but mixed three birdies with two bogeys for a 70. Wholesale Jordan Retro 13 . 10 Texas A&Ms offence dominated as usual against SMU. http://www.cheapairjordan13.com/ .ca looks back at the stories and moments that made the year memorable. Air Jordan Retro 13 For Sale . Robinson finished with 17 points, all but two in the second half, and Lawson had 14 after halftime and finished with a game-high 11 assists as the Nuggets handed Dallas its first home loss in eight games this season. J.J. Hickson led Denver with 22, and Kenneth Faried added 10 points and 10 rebounds. Cheap Air Jordan Retro 13 . -- Five former Kansas City Chiefs players who were on the team between 1987 and 1993 filed a lawsuit Tuesday claiming the team hid and even lied about the risks of head injuries during that time period when there was no collective bargaining agreement in place in the NFL. After an impressive 2015 season, Stanford Steve Coughlin of SportsCenter with Scott Van Pelt and Chris Fallica of ESPN Stats & Information and College GameDay are back. Every week during the college football season, theyll give their best bets for the weekends top college football games.dddddddddddd ' ' '