Here's what you need to know about Theranos, a biotech company founded in 2003 by Stanford dropout Elizabeth Holmes. (Jayne Orenstein/The Washington Post)

Years before Theranos, the Silicon Valley upstart that promised to revolutionize blood testing, came under harsh public scrutiny in October, a military official raised concerns that the secretive company was violating federal law.

E-mail correspondence obtained by the Post reveals that an official evaluating Theranos’s signature blood-testing technology for the Department of Defense sounded the alarm in 2012 and launched a formal inquiry with the Food and Drug Administration about the company’s intent to distribute its tests without FDA clearance — a problem that has resurfaced this year, leading Theranos to temporarily stop offering almost all of its tests.

Chief executive Elizabeth Holmes, the company’s superstar founder, asked an ally at the highest level of the military to squelch those “inaccurate” concerns in 2012, but similar issues with regulatory approval now threaten to temper expectations of the highly celebrated startup. Theranos had attracted widespread praise and a $9 billion valuation for its blood tests, which use only a few drops of blood from a finger prick instead of a full vial drawn with a needle.

The technology has been dogged by questions about its compliance in recent months, but the e-mails show some of those issues long predated the current controversy. Theranos denies that it needed FDA approval in 2012, when the blood tests were simply under review for a military research project. But the tests are now commercially available, and in September, the FDA flagged a key component of Theranos’s blood collection technology as an unapproved medical device.

[Read more: A comprehensive guide to Theranos’s troubles and what it means for you]

In the e-mail correspondence, Holmes appealed to four-star Marine Gen. James Mattis to intervene and dispel the military reviewer’s “blatantly false information” about the company. (The reviewer’s name was redacted from the e-mails sent to The Post.) In her lengthy note to Mattis in August 2012, Holmes said that violating FDA law is something “we have never done and of course would never do.”

In a statement to The Post, Theranos said the military was interested in modifying its blood tests for a rugged battlefield environment, a pilot research project that would not have required standard regulatory approval. But the military reviewer’s concerns apparently were broader than that project and foreshadowed Theranos’s current problems with the FDA.

This summer, the agency cleared the company’s technology for a single test, herpes. Theranos has recently stopped using its proprietary fingerstick technology for all other tests, pending FDA approval.

In recent months, Theranos has characterized its decision to engage with FDA regulators as voluntary and forward-thinking. A spokeswoman said the company was committed to FDA regulation as early as 2010, although it didn’t actually begin seeking clearance for its tests until 2013.

“The truth is that we initiated our work to take our laboratory-developed tests through the FDA clearance process over two years ago — by choice, not necessity,” the company said in a statement posted on its Web site in late October.

FDA spokeswoman Jennifer Corbett Dooren said the agency could not comment.

A falling star

Theranos had become a media darling, featured on the covers of Fortune, Forbes and Inc. during the past two years. In 2013, it began offering its blood tests in Walgreens drugstores in Arizona and California. Holmes, its 31-year-old leader who habitually wears a black turtlekneck and has drawn comparison to Apple co-founder Steve Jobs, built a network of politically powerful allies. She filled the company’s board of directors with former government officials and military leaders, many of whom have little expertise in medicine or health. In 2013, a year after he pushed for the technology to be tested by the military, Mattis joined the Theranos board of directors.

Mattis declined to answer specific questions about the e-mails or Theranos technology, but gave a statement in support of the company.

“Theranos had demonstrated a commitment to investing in and developing technologies that can make a difference in people’s lives, including for the severely wounded and ill,” Mattis said. “I had quickly seen tremendous potential in the technologies Theranos develops, and I have the greatest respect for the company’s mission and integrity.”

[Read more: What happened when I tried the new blood test that was promised to change the world]

In October, a Wall Street Journal investigation revealed the company was running most of its tests on devices made by other firms instead of its own “breakthrough” technology. The Journal reported that former Theranos employees and executives of Safeway had questioned the accuracy of the tests.

A military ally

The 2012 correspondence between Mattis and Holmes provides a rare window into how Theranos and its leader operate.

According to a Theranos spokeswoman, Mattis and Holmes met in 2011 at a Marine Memorial event. Mattis, busy overseeing the war in Afghanistan as commander of the U.S. Central Command, expressed interest in testing Theranos’s technology in combat areas, according to the e-mails.

“I’ve met with my various folks and we’re kicking this into overdrive,” Mattis wrote to Holmes in June 2012. “I’m convinced that your invention will be a game-changer for us and I want it to be given the opportunity for a demonstration in-theater soonest.”

He urged Holmes to call or e-mail him if she felt they needed to talk.

A month later, frustrated by the military regulatory expert who had contacted the FDA, Holmes took him up on that offer.

“I know how incredibly busy you are but thought it was the right thing to let you know the following,” Holmes wrote.

She noted that a deputy director working for a division of the military that oversees regulatory issues and compliance had launched a formal inquiry to regulators without warning Theranos.

“I would very much appreciate your help in getting this information corrected with the regulatory agencies,” Holmes wrote in the e-mail to Mattis. “Since this misinformation came from within DoD, it will be invaluable if this information is formally corrected by the right people in DoD.”

Within hours, Mattis forwarded the exchange to military officials, asking “how do we overcome this new obstacle.”

“I have tried to get this device tested in theater asap, legally and ethically,” Mattis wrote. “This appears to be relatively straight-forward yet we’re a year into this and not yet deployed.”

The field demonstration Mattis was seeking never took place.

In late July 2013, two months after he retired from the Marine Corps, Mattis asked a defense department ethics official about future employment with Theranos’s board of directors.

Mattis got the okay, with a restriction.

“Absent additional information regarding your personal or substantial participation in potential procurement of the Afghanistan pilot test of the Theranos device ... I further advise you not to represent Theranos before the DoD [Department of Defense] and DON [Department of the Navy] on that particular matter for the lifetime of the matter,” Robert D. Hogue, counsel for the Marine Corps commandant, wrote to Mattis in a letter provided by Theranos.

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