"All consent forms are read to participants, regardless of their education," said Herman, who added that all participants are identified by numerical code instead of by name.

But Zahner's complaint argued that Harvard was taking advantage of Chinese participants.

"Cheaper, larger and faster genetics studies are possible in China only because the country has not yet established the legal, environmental, workplace and medical protections afforded to American citizens," Zahner wrote.

Herman countered this critique by saying that research in other countries--not just China--is needed to make any breakthroughs in the medical field.

"The only way to understand these conditions is by studying large populations and finding patterns," Herman said. "We're looking for the best way to prevent diseases."

Zahner, who has since left SPH, could not be reached for comment.

SPH Professor David C. Christiani, who has conducted studies in China for over 20 years, said that any complaints against his work have "no foundation at all."