Aaron Quoc Khieu stood before potential investors in a Minnetonka conference room in 2012 and talked up a medical device that he had helped design and was getting ready to put into production.

He had a manufacturer lined up in Vietnam and plans to sell the device in the United States and elsewhere.

Problem was, federal prosecutors say Khieu didn't own the technology for the new balloon-catheter system he called "Snowcat."

They say his former employer, Boston Scientific, did.

Khieu, 47, of Maple Grove, was indicted by a federal grand jury on 14 counts of wire fraud and theft of trade secrets. Unsealed Friday, the indictment describes Khieu as a corporate thief who used a thumb drive to pilfer more than 100 files from Boston Scientific's internal document management system.

Khieu, whom the indictment describes as a longtime engineer at Boston Scientific, has pleaded not guilty to the charges. He said in a statement to the court Friday that his lawyer is still reviewing discovery materials in the case.

"I understand it will take significant time to carefully review each document," Khieu said, "and these allegations may require the services of a scientific expert, which will also take time."

The indictment says Khieu helped design the specialized heart catheters whose designs and manufacturing data he later stole from Boston Scientific, a leading medical device maker that employs thousands in the Twin Cities. He then allegedly tried to recruit investors for a new company, Snowflake Medical.

After his indictment, Khieu was arrested and released on a $25,000 recognizance bond on Oct. 1, but prosecutors kept the matter sealed until late last week because of an unusual detail in the case: Khieu is charged with stealing information relating to at least one product that isn't yet on the market. That means all court documents have to be scrubbed of the still-secret details that Khieu is accused of stealing.

Charges span 'long period'

The indictment makes reference to three devices, but only two are available on the market: the Sapphire and Mustang balloon catheter systems, which inflate surgical balloons inside of blood vessels to squish arterial blockages.

The name of the third device, and any other trade secrets in the case, will be sealed until the technology has been patented, according to a protective order signed Monday by U.S. Magistrate Judge Tony Leung.

"I understand from my attorney there are a large amount of documents, most of which are covered by a protective order," Khieu wrote in court files.

A spokeswoman for Boston Scientific declined to comment on the indictment, citing an ongoing investigation by the FBI. Khieu's defense attorney did not return a call for comment.

The court records don't say when Khieu left Boston Scientific, though he wrote in court files that the charges span "a long period of time" when he worked there.

Prosecutors say that on Oct. 8, 2012, Khieu used a thumb drive to download internal documents about Boston Scientific balloon catheters, including technical prints, manufacturing techniques and details about product composition.

The theft allegedly occurred a month after Khieu e-mailed multiple potential investors to see if any of them were interested in becoming "angel investors" in the balloon-catheter company he would come to call Snowflake Medical. Separately, he contacted a firm in Ho Chi Minh City to ask about how to sell medical devices, including balloon catheters, in Vietnam.

That December, Khieu met with potential investors in Minnetonka and discussed a recent trip to Vietnam, where he told those in attendance that he had met with doctors and hospital administrators to sell catheters. In reality, the indictment says, the catheters were based on the Boston Scientific design.

The catheters were to be manufactured in Vietnam and sold in the United States, Vietnam and elsewhere, the charges say.

Authorities executed at least three search warrants in the case, including one on May 31, 2013 — which was just three days after Khieu allegedly e-mailed a copy of his Snowflake business plan to an employee for an unnamed device firm that competes with Boston Scientific in Vietnam.

Joe Carlson • 612-673-4779

Twitter: @_JoeCarlson