“Even I find it strange,” Cho said of his daughter being listed as the main author in the medical study, at a press conference held Sept. 2 where he denied irregularities. “Authorship standards may have been loose or ambiguous at the time,” he said. “I think she was credited for translating the research into English.”

The Korean Society of Pathologists retracted the paper on Sept. 5, for falsely stating that it had received ethical approval from an institutional review board when it fact it had failed to do so. The society also took issue with the listing of authors who had not made the required contributions to the study, including Cho Min.

Next in line for subpoena is likely the justice minister’s wife.

Chung, a professor at Dongyang University, faces allegations that she fabricated a certificate using the seal of the university president in 2012. The certificate was submitted as part of Min’s medical school application.

Prosecutors indicted Chung on Sept. 6, the day of her husband’s National Assembly confirmation hearing, over charges of document forgery.

Chung, who was hospitalized last week, has appointed a defense team of 14 seasoned lawyers.

In a separate investigation into alleged financial irregularities involving the Cho family, Cho Beom-dong, 36, became the first in the family to be arrested Monday afternoon on charges of embezzlement and other offenses. Chung was charged without being arrested.

The minister’s cousin once removed is believed to be the de facto head of Co-Link Private Equity, the operator of a fund in which Chung, the couple’s two children, her brother and his two children invested a combined 1.4 billion won.

Two companies funded by Co-Link -- Wealth C&T and WFM -- saw surge in profits by winning government projects after the Cho family invested in them.

In the latest development in what has come to be known as “Cho Kuk private equity” affair, WFM’s ex-president, surnamed Wu, was called in Tuesday for questioning. Wu left the country in end-August together with Cho’s relative, and presidents of Co-Link and Wealth C&T, a move which prosecutors interpreted as attempted flight.

By Kim Arin (arin@heraldcorp.com)