Tom English: 'For all the intrigue, the bottom line is that Big Brown is a drugged horse'

RIGHT OUT of Hollywood this one. Right out of the same fantasy factory that produced the book and the film of the remarkable life of Seabiscuit, the improbable hero of American horse-racing of the 1930s, the small, crooked-legged animal that became a national icon. For Seabiscuit back then read Big Brown now.

There are some can-do people in the movies already working on his story, already convinced that come Saturday Big Brown is going to add the Belmont Stakes to the Preakness and the Kentucky Derby and thereby complete the storied Triple Crown, the first horse to do so since the great Affirmed managed it in 1978. In the last dozen years seven thoroughbreds have won the first two legs of the Crown but none could close the deal on history. This one, they say, is different. The way he's beaten the opposition to date – trampled them underfoot without ever having to hit top gear – suggests he will romp home in New York this weekend. As soon as he's past the winning post, Hollywood will be mobilised for sure.

It's not just the horse that thrills but the back story. Especially the back story. The drugs and the disputes, the murder and the conceit. It's all there. It's all encapsulated in the life of Big Brown's trainer, Rick Dutrow, a blow-hard with a past that nobody could mistake for conventional.

Rick is the son of a famous trainer, Dick Dutrow, a legend in American racing. In the late 1990s they became estranged after a bitter falling out. Dick has died since but Rick still hasn't gone to his grave, hasn't found it within himself to visit. Whatever demons remain they're taking an awful lot of shifting.

At the time, Rick was a drop-out without a buck to his name. Literally. He was living in a dirty tackroom in Barn 1 of the Aqueduct racetrack and would get a dollar off his mate for a morning coffee. He was a drug user with terrible gambling debts. He was separated from his wife and daughter and on the road to ruin. The guy was a loser.

His family never did care for Denise, his wife. In 1994 their daughter, Molly, was born, but Rick wasn't entirely sure the girl was his. It was that kind of relationship. Only it was worse. Denise had a dark secret. She, too, was a drug abuser, hooked on crack sold to her by a young Queens dealer called Patrick Jeanty. In 1997, with her marriage broken and her life in freefall, her and Jeanty fell out. Jeanty thought she was going to shop him to the police so he came to her home with two accomplices and choked and beat her. Molly, aged two and a half, was in the next door room as the murder took place.

Molly went to live with her troubled father. "I'm his good luck charm," she says. By 2000 he was getting his life in order. His training career had taken off in a big way, his feats bringing him three prestigious awards in 2001, 2002 and 2005 but all the time there was this thing about the drugs. His own recreational gear had landed him in trouble many times and saw him warned off and banned at tracks in New York. Briefly, he had his permit suspended for testing positive for pot. What he did to his own body was not of huge import, but what he was injecting into his animals was an altogether different affair.

In 2005 Dutrow was suspended for 60 days when two of his horses tested positive for banned substances, an offence he has repeatedly been pulled up for over the last eight years. A few weeks back he admitted that in the middle of every month Big Brown, this darling of the nation, gets a shot of the anabolic steroid Stanozolol, the drug made infamous by Ben Johnson in the 1988 Olympics.

This part of the tale might prove a challenge to the romantic ideal of the film makers. Steroids in racing are only banned in ten states in America. None of the three states where the Triple Crown is run are among them, so Dutrow is not breaking any law, not technically, though the law may soon change. Even if he was, the punishment would be puny. Last year in Iowa, where steroids are illegal, a trainer was given a $300 fine after one of his horses tested positive for a banned drug.

Some media outlets in America have raised these issues and have questioned the legitimacy of Big Brown's claim to greatness, but mostly there has been cheerleading. Lots and lots of pompom wielders have danced across this story. Sports Illustrated magazine did a sizeable profile piece of the horse recently and failed to mention steroids once. They want the fantasy badly. They want to believe in this horse's purity, in his greatness, in his innocence. Instead of focusing on the morality of Dutrow's methods they instead concentrate solely on his fantastically strange life and the heartwarming tale of Big Brown's jockey, Kent Desormeaux.

Desormeaux is the 38-year-old father of Jacob, aged nine. Jacob is a brave little boy diagnosed some time back with Usher Syndrome, a condition that causes deafness and gradual loss of vision. He's had 11 different surgeries to try and cure it but no joy so far.

His dad has come agonisingly close to winning the Triple Crown in the past. In 1998 he went to Belmont with two parts of the Crown to his credit on board Real Quiet, but lost his place in the pantheon of great riders by a nose to Victory Gallop. He was based out in California and his career had long since stalled by 2006. "In California trainers were walking away from me when I came to their barns in the morning. It was, 'Oh no, here comes Desormeaux'."

Desormeaux has done a fantastic job of steering Big Brown and there are not too many observers over the water that will back against him completing the Triple Crown on Saturday. Angel Cordero, one of the greatest jockeys American racing has ever known, is heading the fan club. "Big Brown has the size, the mentality, the stride and the acceleration," he says. "He's like a car that comes with everything. Just step on it and you're there."

Certainly, Dutrow is convinced. He's a fascinating man but a pompous man to boot. He has belittled the opposition at Belmont and has insulted one or two connections. Casino Drive, a Japanese horse, is considered his main danger on Saturday. Dutrow says he's told Desormeaux to "find Yamamoto and chew his ass". Mention of the general who conceived the Pearl Harbour attack was not Dutrow's most subtle moment. Then again, he doesn't have many, it seems.

Writing in the Racing Post, Brough Scott had this to say: "The facts are that on the same day that we celebrate our Derby at Epsom, our racing cousins over the water are asking the world to applaud a performance by an athlete that would be immediately invalidated for anabolic steroids in every other major racing territory."

That's the truth. However glorious it may seem, it is unreal, for all the intrigue in the story the bottom line is that Big Brown is a drugged horse. Of course, in time Hollywood may chose to remember him differently. If he wins on Saturday, you can bet on it.