The athletic brunette at the center of a media firestorm following South Carolina Gov. Mark Sanford's confession of an affair is a 43-year old Buenos Aires resident who lives in an upscale apartment building, FOXNews.com has confirmed. 

Her name is Maria Belen Chapur, and local media in Argentina have identified her as Sanford's mistress. 

She lives in a 14-story apartment building next to the Buenos Aires Zoo, in a trendy neighborhood that is also near the U.S. Embassy. 

A witness who works in the building described her to Buenos Aires Continental Radio as a beautiful brunette with big eyes who plays tennis on a nearby lawn and runs every morning in her neighborhood. 

The witness told the radio station that someone matching Sanford's description arrived at the complex, alone, with a small sports bag last week and asked to go inside the building. 

Sanford admitted Wednesday to having an affair over the last year and covering up a secret trip to visit his mistress last week. The admission rocked the South Carolina political scene and has also captured the attention of the Buenos Aires media, as the governor provided few details about his lover. 

Terra Noticias reported that Chapur speaks several languages, including English, Portuguese and Chinese. It reported that Chapur works for Bunge y Born, but a representative for the agribusiness firm told FOXNews.com that is incorrect. 

Reports said she devotes much of her time to working out and that she ran in two 10-kilometer races this past year. 

Click here for a Liveshots blog on Sanford's struggles as governor. 

Click here for a Liveshots blog on Sanford's criticism of former President Bill Clinton's affair. 

In personal e-mails published Thursday by South Carolina's The State newspaper, the mistress reveals little about her professional life. But the intimate tone of the apparent exchanges between her and Sanford suggests the affair was far more just a south-of-the-equator fling. 

Like star-crossed lovers, the two wrote of their "impossible love," and while the mistress's English was at times imperfect, the two expressed deep feelings for each other using language that was more poetic than lurid. 

The e-mails were steamy, as one might expect of any forbidden love. 

"My heart cries out for you, your voice, your body, the touch of your lips, the touch of your finger tips and an even deeper connection to your soul," Sanford wrote in one of the e-mails, dated last summer, even as Sanford discussed taking a tour through Asia with his family. 

In the e-mail, dated July 10, 2008, at 12:24 a.m., he wrote, "You have a particular grace and calm that I adore. You have a level of sophistication that so fitting with your beauty. I could digress and say that you have the ability to give magnificent gentle kisses, or that I love your tan lines or that I love the curve of your hips, the erotic beauty of you holding yourself (or two magnificent parts of yourself) in the faded glow of the night's light - but hey, that would be going into sexual details ..." 

Sanford's e-mails, which the newspaper said it acquired in December 2008 but couldn't authenticate until Sanford's confession, became more intimate as the month progressed, while the mistress's were deep and personal from the start. 

"I would (have) stayed ... kissing you forever," the woman identified by The State only as "Maria" wrote in a July 4, 2008, e-mail, calling Sanford "my beloved." 

In another, she explained that she is not in love with another man, whose identity is not revealed. 

"You are my love ... something hard to believe even for myself as it's also a kind of impossible love, not only because of distance but situation," she wrote. "I'll dream with you." 

On July 10, 2008, she wrote about how hard it was to "figure all this out" and concluded, "I am not interested in knowing." 

"I prefer to think we'll see each other again somewhere sometime in this life and in next. Will be missing you till then," she wrote. 

Her "P.S." was the most suggestive of the published e-mails. 

"P.S.: I don't want to put the genius (sic) back in the bottle because I truly believe in freedom. I never gave you sexual details but now you don't need to imagine you can close your eyes and just remember. I'll do the same," she wrote, according to The State. 

Click here to read more about the e-mails in The State.