Convicted Theranos founder Elizabeth Holmes on Monday asked for a new trial, saying a star prosecution witness showed up at her home saying he felt he had "done something wrong."

Holmes is scheduled to be sentenced in October after a jury early this year found her guilty of defrauding investors in her blood-testing startup Theranos.

Holmes is a rare example of a tech exec being brought to book over a company flaming out, in a sector littered with the carcasses of money-losing businesses that once promised untold riches.

Her case shone a spotlight on the blurred line between the hustle that characterizes the industry and outright criminal dishonesty.

But attorneys for Holmes said that former Theranos lab manager Adam Rosendorff, who was part of the prosecution's case, arrived unannounced at her California home in August looking disheveled and saying he needed to speak with her.

"He said he feels guilty, it seemed like he was hurting," Holmes's partner William Evans said of Rosendorff in an exhibit with the court.

"He said when he was called as a witness he tried to answer the questions honestly but that the prosecutors tried to make everybody look bad (in the company)."

Evans said he turned Rosendorff away from the home he shares with Holmes and their young son, telling Rosendorff that Holmes could not speak with him.

"He said he thought it would be healing for both himself and Elizabeth to talk," said Evans."

Evans recounted Rosendorff saying that both he and Holmes were just starting out in their careers when they worked together at Theranos, and that "everyone was working so hard to do something good and meaningful."

Holmes had vowed to revolutionize health diagnostics with self-service machines that could run an array of tests on just a few drops of blood, a vision that drew high-profile backers and made her a billionaire on paper by the age of 30.

She was hailed as the next tech visionary on magazine covers and collected mountains of investors' cash, but it all collapsed after Wall Street Journal reporting revealed the machines did not work as promised.

Jurors found her guilty of four counts of tricking investors.

But the jury also acquitted her on four charges and could not reach a verdict on three others.

The 38-year-old now faces the possibility of decades behind bars.

Attorneys for Holmes argued that Rosendorff was a star witness for prosecutors, and that his statements put the guilty verdict in doubt.

"If the jury had heard from Dr. Rosendorff that the government cherry-picked evidence to make things seem worse than they were and that everyone was doing their best and working hard to do something good and meaningful, the jury would have viewed this case very differently," Holmes attorney Amy Mason Saharia argued in the filing.

Holmes is asking for a new trial, or at least a hearing in federal court in Silicon Valley to dig deeper into what Rosendorff meant to tell her at her home, attorneys said.

"He said he wants to help her," Evans said of Rosendorff.