Story highlights The e-mails have been posted online anonymously

They suggest an affair between the nominee and a Wall Street Journal reporter while both worked in Iraq

The pair later married

The State Department is standing by McGurk for the nomination

The Obama administration's nominee for the next U.S. ambassador to Iraq has run into new opposition thanks to the publication of some racy e-mails suggesting an affair with a Wall Street Journal reporter while both worked in Baghdad.

The cache of e-mails were posted online anonymously this week, first on photo-sharing site Flickr and then on the blog Cryptome. The messages are purportedly from 2008 between Brett McGurk, a top adviser on Iraq to then-President George W. Bush, and reporter Gina Chon.

CNN has not independently authenticated the e-mails. U.S. State Department spokeswoman Victoria Nuland wouldn't confirm or deny their authenticity: "They're out there for everybody to see. ... I'm not going to get into e-mails between Mr. McGurk and the woman who subsequently became his wife."

While in Baghdad, McGurk was working on delicate negotiations with the Iraqis over a potential status of forces agreement, while Chon covered the progression of those talks for the newspaper.

In a June 20, 2008, chain, the e-mails show McGurk thanking Chon for "the dinner conversation."

"Please let me know when you might want to get together. I'll tell you what I know, if you can teach me about cars," he says, according to the e-mails posted online.

"wow, you are a good person to know," Chon replies.

In the ensuing banter, she apparently compares reporters seeking a scoop to vultures. His reply: "If treated to many glasses of wine -- you could be the chosen vultures."

Another e-mail shows McGurk telling Chon, in part: "I had a very good day with the Iraqis -- the best yet. Can't tell you about it of course. But you should definitely stay past Sunday."

Her reply: "Stop being such a tease!"

McGurk had been married to another woman in 2006, but it is not clear whether he was still married at the time of his alleged 2008 e-mail exchanges with Gina Chon. The pair later married.

During a particularly flirty exchange posted online, McGurk appears to boast that he could bring her to a dinner with a top Iraqi politician: "I totally have rank to get you in here." He later dismisses the idea, and there's no indication of whether he provided exclusive information to Chon.

Nevertheless, "it is hard to avoid the impression from these e-mails that sensitive information was leaked in the context of a romantic relationship at a time when this now-candidate to be ambassador to Iraq was engaged in extraordinarily sensitive negotiations," said media analyst Howard Kurtz, host of CNN's "Reliable Sources."

Repeated attempts Friday to reach McGurk and Chon through phone calls and e-mails were unsuccessful.

McGurk appeared Wednesday before the Senate panel considering his nomination, but was not asked about the e-mails posted online.

Still, McGurk's nomination faced criticism from some high-ranking Republicans, including Sen. John McCain, even before the e-mails surfaced, namely over policy differences.

"Prior to these e-mail revelations, I had reservations," said Sen. James Risch, R-Idaho, who is on the Foreign Relations Committee. "Now that additional issues have been raised, more information will be needed," he said.

Another committee member, Sen. James Inhofe, R-Oklahoma, said through a spokesman that he will not meet with McGurk, as he usually would with a nominee, until his concerns over these issues are resolved.

However, Nuland at the State Department defended McGurk's nomination.

"He is, in our view, uniquely qualified to serve as our ambassador, and we urge the Senate to act quickly on his nomination," she said.

A Wall Street Journal spokeswoman said, "We are looking into the matter." Chon requested a leave of absence in March, she said, which is scheduled to begin later this summer.

Other e-mail exchanges posted online are filled with sexually suggestive content about pouting and nurses and being alone together.

In one message, McGurk appears to be planning to give his security detail the slip: "I'll provide plenty of warning before coming by. I need to figure out how to lose my goon squad. They tend to mar my most secret and clandestine missions."

One of his later e-mails recounts the trajectory of his pursuit: "... from my first message to you through our Chinese dinner to the (expletive) banter and then my coming over to hook up with you for the first time (on June 23 -- a night the world should celebrate)," he writes, "I am so (expletive) smooth!"