Throughout its colorful history, Las Vegas has seen its share of shadowy characters and suspicious backroom deals. But the latest opaque transaction in the city doesn’t involve one of its gambling dens. It involves its leading newspaper.

The Las Vegas Review-Journal was sold last week for $140 million to a buyer who . . . well, that’s the problem. The purchaser is a recently incorporated outfit called News + Media Capital Group, about which almost nothing is known. Efforts to find out more have crapped out. In the great Vegas tradition, everyone in the know has dummied up.

The secretive deal has thrust the newspaper, which is in the business of finding out things, into the odd position of being unable to tell its readers who owns it.

“It’s been an amazing few days,” said one of the paper’s many exasperated journalists, speaking on the condition of anonymity so as not to upset his new boss or bosses, whomever they may be. “From the very start, this has been a disaster.”

In the absence of any hard news, speculation about the identity of the new owner has been brisk. The betting is that a wealthy Vegas denizen, such as casino owners Sheldon Adelson or Steve Wynn, or Zappos.com founder (and local real estate redeveloper) Tony Hsieh is behind the purchase. Some have even suggested Hustler publisher Larry Flynt, who on Monday took an ad in the Review-Journal to raise questions about Republican candidate Ben Carson’s relationship with Armstrong Williams, Carson’s business manager and campaign adviser.

Although print circulation of the Review-Journal has fallen along with most newspapers (it sells about 98,000 copies daily, 119,000 on Sunday), it remains a prime target for anyone seeking to influence voters in Nevada. The state will be the third in the nation to hold a Democratic primary (Feb. 20) and the fourth for Republicans (Feb. 23), giving it a pivotal role.

On Tuesday, Sen. Harry M. Reid (D-Nev.) suggested that Adelson — a prominent Republican donor — might be the buyer. Adelson hasn’t commented.

Other politicians have been raising questions. After with the newspaper’s editorial board on Monday, a day before the Republican presidential debate in Las Vegas, former Florida governor and GOP presidential candidate Jeb Bush tweeted about the session: “Only q left unanswered — who owns the newspaper?”

The mystery surrounding the Review-Journal began last Thursday when the paper’s journalists were called to what they assumed would be a routine all-staff meeting. After lengthy preliminaries, publisher Jason Taylor got to the point: The paper, he said, had been sold a day earlier by its owner, New Media Investment Group, to News + Media.

But the newspaper’s efforts to report the news about itself immediately ran into trouble. Reporters said they were rebuffed by Taylor and a representative of News + Media, Michael E. Schroeder, when they asked for details about the company.

The paper’s news story about the sale initially included Schroeder’s response to a question about why he wouldn’t disclose the identity of News + Media’s investors. Schroeder was quoted as saying: “They want you to focus on your jobs. Don’t worry who they are.”

The quote was removed from later print and online editions on Taylor’s orders, according to several people at the newspaper.

Schroeder and Taylor did not reply to requests for comment. Review-Journal editor Mike Hengel referred a request for comment to Michael E. Reed, the chief executive of GateHouse Media, a subsidiary of New Media Investment Group that is continuing to manage the newspaper. Reed didn’t respond.

In any case, whoever bought the paper really seems to have wanted it. The $140 million price tag is a rich premium over what New Media Investment Group paid for the paper and related publications just nine months ago. The company’s $102.5 million purchase of Stephens Media, the Review-Journal’s former owner, in February valued the Review-Journal by itself at around $80 million, according to people at the newspaper.

The $140 million deal suggests that the latest buyer paid about $60 million, or 75 percent, more than the paper sold for only nine months earlier.

Given the declining prices for newspapers, the Review-Journal’s high-roller price tag seems to defy market sense. “All I can figure is that someone bought a lot of silence with that money,” a Review-Journal journalist said.

Said another, reflecting another bit of Vegas history: “At least when the mob made a deal for a casino, it made money. But the mob’s too smart to buy a newspaper. There’s no money to be made.”