Stephen Jimenez didn’t set out to be the most dangerous journalist on earth.

Or, more to the point, the most dangerous gay journalist.

But Jimenez unearthed a story that few people wanted to hear. And it calls into question everything you think you know about the life and death of one of the leading icons of our age.

Matthew Shepard, college student. Killed, at 21, for being gay.

Or was he?

Jimenez’s “The Book of Matt: Hidden Truths About the Murder of Matthew Shepard,” out last month, challenges every cultural myth surrounding Shepard’s short life and unspeakable death. After some 13 years of digging, including interviews with more than 100 sources, including Shepard’s killers, Jimenez makes a radioactive suggestion:

The grisly murder, 15 years ago this month, was no hate crime.

Shepard’s tragic and untimely demise may not have been fueled by his sexual orientation, but by drugs. For Shepard had likely agreed to trade methamphetamines for sex. And it killed him.

Heresy.

Why dredge this up now? Jimenez’s answer surprised me.

“As a gay man,” he said, “I felt it was a moral thing to do.”

Aaron McKinney and Russell Henderson, now doing life for murder, were not homophobes, writes Jimenez. Shepard was lured from a bar, then driven to the outskirts of Laramie, Wyo., where he was robbed. McKinney savagely pistol-whipped Shepard with the barrel of a .357 Magnum. The men then hung him, barefoot, freezing and barely alive, on a fence, in a pose resembling a crucifixion. He died six days later.

But McKinney was no stranger. Strung out on meth for a week before the slaying, writes Jimenez, McKinney likely had been Shepard’s gay or bisexual lover.

“To understand who Matthew really was,” Jimenez said, “to alter our perception of him as a martyr and an icon, is not going to be damaging to gay rights.

“I don’t buy it. I don’t think we have anything to lose from telling the truth.”

Activists, journalists, politicians and filmmakers who, with the best of intentions, based careers on Shepard’s murder are furious. But Jimenez insists he’s willing to trade Shepard’s irreproachable image for a serious talk about drugs. Meth, he said, is haunting the gay scene, bringing with it a plague of ultra-violence, new HIV infection — and gay-bashing.

If this book saves one life, it’s worth it.

Jimenez, 60, a Brooklyn native who splits his time between New York and Santa Fe, NM, has seen his work attacked by organizations from the Gay and Lesbian Alliance Against Defamation to the Matthew Shepard Foundation, which helped push through a 2009 federal hate-crimes law in the name of Shepard and James Byrd Jr., the black man dragged to his death behind a pickup truck in Texas in 1998.

The New York Times Magazine commissioned, then canceled, a piece from Jimenez in 2004. (The editor claims it wasn’t any good.) But ABC’s “20/20” ran with a story Jimenez produced, which won two major broadcasting awards. Yet the Southern Poverty Law Center’s Hatewatch blog recently accused Jimenez of serving as a lapdog of “right-wing pundits, radio hosts and bloggers.”

In Washington, DC, gay activists pestered bookstores to cancel Jimenez’s appearances. So much for free speech.

“It’s offensive,” said Jimenez.

I find it offensive that a gay journalist should be held to a different standard than a straight one. But Jimenez’s every word has been vetted by protectors of Matthew Inc. to determine his agenda. Is he a traitor to the cause?

Jimenez is not the enemy. He’s just a man who told an uncomfortable truth, as he saw it.

He should be proud.

Back after sLho start

Nice to have you back, Joe.

After waging a sleepy campaign against tax-loving, cop-cuffing Democratic mayoral front-runner Bill de Blasio, Republican challenger Joe Lhota finally turned up the fire.

“I’m back!’’ he exclaimed after a spirited showing in last week’s debate.

De Blasio accused Lhota of “race baiting’’ by airing an ad that vividly suggested this city will return to the old, crime-ridden days if de Blasio is elected.

“I was shocked!’’ Lhota bounced back. “He threw out the race card as if it was 25 cents in his pocket.’’

Lhota said in a Midtown speech that de Blasio, who has been in city government for two decades, has to take some blame for turning New York into what he calls a “tale of two cities’’ — wealthy haves and poor have-nots.

It’s about time you got in the game, Joe. Let’s hope it’s not too late.

It’s time to get the El outta here

Delusional ex-Love Gov Eliot Spitzer, whose hooker-hiring ways led to his trouncing in the Democratic primary for city comptroller (voters went for Scott Stringer), isn’t done messing with our heads.

The Post’s Richard Johnson reported that Spitzer was overheard boasting over a Midtown lunch of kosher sushi and prime steaks that his disastrous showing among voters will only make it easier for him to run for another office! (A Spitzer spokeswoman denied he’s eyeing an office.) An ego this big doesn’t vanish in the cold glare of reality. Get a real job, Eliot.

Running rings around Kanye’s rock

Does size matter?

Kim Kardashian said “Yes’’ to Kanye West’s marriage proposal, accepting a huge, 15-carat diamond ring designed by Lorraine Schwartz. But is it big enough?

The rapper and father of Kim’s baby girl was outdone in the sparkler department by Kim’s ex-hubby Kris Humphries, who in 2011 presented his lady love with an engagement ring by the same designer, bearing a 16.21-carat center rock and two side diamonds of 1.8 carats apiece. That’s 19.81 carats of bling.

(Originally valued at $2 million, the bauble sold at a Christie’s auction this month for a paltry $749,000.) It wasn’t clear which gem is worth more. Kanye’s diamond is described by Schwartz as flawless. Kris’ was big enough to give Kim carpal tunnel syndrome — and that union lasted just 72 days. Will the Kimye marriage make it?

Kanye might consider taking another trip to the lucky jeweler.

It’s love, by George

True love can’t be faked. Prince William barely took his eyes off his infant son, Prince George, as the proud daddy held the child in his arms during a christening that attracted four generations of royals, including George’s great-granny, Queen Elizabeth.

Parental warmth, formerly in short supply among the House of Windsor, is making a comeback, brought into vogue by William’s late mom, Princess Diana. As a veteran royal hater, I find myself saying, “Awww!’’

There is hope for this family.