Earlier in the day in the US District Court in San Jose, federal prosecutors and the defence presented a variety of Theranos financial data to jurors, much of it focused on revenue projections that prosecutor Robert Leach said had been approved by Holmes.

But Holmes lawyer Lance Wade was quick to get the day’s first witness, former company finance chief So Han Spivey, to note that Balwani — who Holmes claims coerced and abused her during a long-running romantic relationship — was involved in producing the projections. Balwani is to be tried separately next year.

During Cheung’s testimony, Judge Edward Davila excused the jury, so lawyers for both sides could argue over whether certain emails could be shown to jurors. Wade, with the jury absent, claimed that Holmes was unaware of much that went on in Theranos’ labs, which Balwani oversaw. Prosecutor John Bostic countered that “substantial evidence” showed Holmes’ involvement in the company in general, and the “pervasive nature” of her communications with Balwani was evidence of her awareness of lab matters.

“These issues filter upward to Ms Holmes,” Bostic said.

Holmes faces up to 20 years in prison. Her trial continued on Wednesday (local time), when Cheung is scheduled to return to the witness stand.