Colorado Democratic congressional candidate Levi Tillemann made a name for himself by designing the high-efficiency IRIS Engine.

He and his younger brother Corban were written up in National Geographic magazine in 2010 and were roundly praised for the innovation. But since 2011 the company, IRIS Engines, has racked up a $255,495 in taxes and fines in Delaware, where it’s incorporated.

The Secretary of State’s Office there says IRIS Engines hasn’t filed a report or had a designated agent in the state since 2010.

Tillemann wanted to speak off the record for context when Colorado Politics asked about the tax bill, but after we asked to stay on the record, his campaign provided a statement, instead.

The campaign blamed questions about the situation on his Democratic opponent in the 6th Congressional District primary, Jason Crow. The two are vying to face incumbent Republican Mike Coffman in November.

“Already caught in a whirlpool of their own lies and deceptions, Jason Crow and his allies have decided to just keep going,” the campaign stated. “The IRIS Engine was an exciting innovation. Under Levi’s leadership, it won awards through NASA, Johns Hopkins, Rice University, and some of the world’s most prestigious technology, design and startup competitions.

“But by 2011 it was clear to Levi that the world didn’t need a better gas engine, it needed to transition away from fossil fuels. Levi turned over control of the company to a relative who wanted to continue to pursue the design. Unfortunately, that relative didn’t understand how to manage elements of the company’s valuation or corporate filings. The first Levi heard of this liability was from a negative push-poll conducted by Crow’s team.”

Levi Tillemann might still have an indirect ownership stake, the campaign said.

It provided a direct quote from Levi Tillemann.

“What this baseless attack shows is that white-collar criminal defense lawyers don’t understand innovation, entrepreneurship or the real economy,” he stated in an apparent reference to Crow. “This should surprise exactly no one.”

The Crow campaign denied doing a push poll around the issue and characterized Tillemann’s response as ‘blame-shifting.'”

Meanwhile, Tillemann’s campaign manager, Juan Rodriguez, exited his post about a month ago and has been replaced by LeAnn Joswick.

Editor’s note: This story has been updated with new information from the campaign on the campaign-manager transition. It also has been further updated regarding ownership and operation of the company.