Amazon officials visited Dallas in February, sources said a day after company officials confirmed plans to visit all 20 of the metro areas the corporate mammoth put on a shortlist for its coveted second headquarters.

And among the vast array of possible sites regional leaders have offered up for Amazon's so-called HQ2, the ones in downtown Dallas seemed to be the frontrunners, four sources confirmed to The Dallas Morning News.

The Dallas Regional Chamber, which coordinated Dallas-Fort Worth’s joint proposal on behalf of the Metroplex’s many cities, declined to comment on Tuesday. A spokesman for Dallas Mayor Mike Rawlings also declined to comment.

The online retail giant has tried to clamp a lid on a slow ooze of information about what started out as a hyper-publicized search.

Amazon upended a traditionally secretive process and sent officials across the continent scrambling when it announced in September that it was looking for a place to put 50,000 new, high-paying tech jobs and to invest $5 billion in a corporate facility on par with its Seattle headquarters.

Cities big and small trumpeted that their business leaders would pitch the company on their merits. Amazon received 238 proposals.

But almost immediately, the backlash started.

As state officials in New Jersey and Maryland dangled multibillion-dollar tax incentive packages to lure the etailer, groups that oppose the use of such incentives began imploring elected officials not to play ball — not to compete against each other using taxpayer money.

After the list of 20 finalists was announced in January, retraining the spotlight on the debate, prominent urbanist Richard Florida started a Change.org petition asking elected officials and community leaders to sign a "non-aggression pact" in the use of "tax giveaways and location incentives."

Around the same time, Amazon reportedly began demanding that local officials keep quiet. That hasn't stemmed the tide of speculation and scrutiny of the company's every move.

On Monday, The Washington Post reported that Virginia Gov. Ralph Northam said he had breakfast with Amazon officials last week in northern Virginia and that Washington, D.C., officials confirmed D.C. Mayor Muriel Bowser had dinner with Amazon representatives.

Still, it’s been unclear whether Amazon favored another urban campus like its Seattle home, which has transformed the Pacific Northwest city. Or whether the company might look for a suburban site where it can spread out a bit more, like its Silicon Valley peers.

D-FW has a wealth of options that fit both bills — though the region's perceived lack of cool cachet among millennial workers has been a concern. Socially conservative politics at the state level, including the narrow miss of legislation that would have restricted transgender people's use of bathroom, have prompted calls from LGBT advocates for CEO Jeff Bezos to avoid Texas entirely.

Rawlings apparently tried to assuage those worries when he told CNBC in late January that Dallas was a "blue city in a red state."

Dallas Regional Chamber officials have closely guarded details of its HQ2 proposal, except to say that they hoped to present a unified front on behalf of the region and that they didn't edit the menu of sites submitted to them by cities and developers.

At the time, Dallas City Council member Philip Kingston called the regional cooperation “complete garbage.” The region’s wealthy suburbs, he said, have an unfair advantage in terms of economic incentives and Dallas has a distinct edge in terms of transit and other urban amenities.

Frisco also took the opportunity for a promotional blitz, releasing its own video aimed at catching Bezos' eye.

Meanwhile, Fort Worth has vowed to step up its corporate recruitment work in an effort to keep the western part of the D-FW area in the mix for major relocations.

Staff writer Maria Halkias contributed to this report.