Theranos founder claims abuse by controlling boyfriend
Fallen biotech star Elizabeth Holmes arrives for the first day of her fraud trial in California (AFP)

Fallen biotech star Elizabeth Holmes fought back tears while testifying at her fraud trial Monday as she recounted alleged abuse by a controlling boyfriend running operations at her failed blood testing startup.

Holmes choked up as she told jurors that ex-boyfriend Ramesh "Sunny" Balwani, whom she'd brought in to help run her company Theranos, denigrated her and forced himself on her sexually when angry about how she was running the company.

"He would get very angry with me and then he would sometimes come upstairs to our bedroom and force me to have sex with him when I didn't want to," Holmes said of Balwani.

Balwani, who served as Theranos' chief operating officer, bullied Holmes to succeed in the business world, she said during her fourth day of testimony in her fraud trial, which began in early September.

Holmes could face decades in prison if convicted on allegations she defrauded investors in her once-hyped Silicon Valley company, which collapsed after its diagnostic machines did not perform as promised.

Balwani, almost two decades Holmes' senior, would criticize her for acting "giddy" or not behaving in ways he considered serious, the now-37-year-old said, as she went through notes and text messages from that time.

"Sunny was saying he was astonished by my mediocrity and he was exhausted with me, that I was a monkey that was trying to fly a spaceship," she told jurors.

Balwani, who is facing trial separately, has denied the abuse allegations, with his lawyer describing them as "salacious and inflammatory" in court filings.

"Ms Holmes' allegations are deeply offensive to Mr. Balwani, devastating personally to him," lawyer Jeffrey Coopersmith wrote.

Holmes was 19 when she launched Theranos in 2003, eventually promising self-service testing machines that could run an analytical gamut cheaply and on just a few drops of blood.

She dropped out of Stanford University in 2004, testifying on Monday that she was raped while a student there, and that she left school to focus on starting Theranos.

Holmes said she believed in the company's technology and did not challenge Balwani's running of the lab, adding she was shocked when the lab failed a regulator inspection in 2016.

She said the relationship ended that year and she replaced the company's leadership, with her brother helping her move out of the home the couple shared while Balwani was traveling in Thailand.

"He wasn't who I thought he was, I thought if I was going to allow the company to see through its potential, I had to do that without him at the company."

Holmes rose to renown while convincing high-profile backers, journalists and business partners that her idea could be translated into reality and could change health care.

Prosecutors contend Holmes and Balwani conspired to defraud investors, doctors, and patients.

Her defense said in opening arguments that she is guilty of nothing more than trying and failing to realize a visionary idea.