China must close the "judicial loophole" of suicide for corrupt officials in its ongoing battle against graft, a well-known scholar said in the official China Daily on Wednesday.

President Xi Jinping has vowed to target high-flying "tigers" as well as lowly "flies" in an anti-corruption drive that has ensnared many high-ranking officials, including the powerful former domestic security chief, Zhou Yongkang, and Jiang Jiemin, once the top regulator of state-owned enterprises.

In a commentary, Lin Zhe, a professor of anti-corruption studies at the ruling Communist Party's Central Party School, said corrupt officials use suicide as a tool to evade punishment by the party's anti-graft authorities.

Corrupt officials who kill themselves can "preserve their titles and honor" as well as their ill-gotten gains, which remain in the hands of their families, she added.

"Considering the astonishing sums of money an official can obtain through corruption, that's a good deal for them and their families," Lin said.

Just 37 percent of officials who commit suicide actually suffer from psychological or other pressure, Lin said.

Some officials may kill themselves to avoid becoming witnesses in bigger cases, she added, saying authorities in China must take measures to "close that loophole."

"It might be difficult to change the principles, such as ending prosecution against dead suspects, but at least disciplinary investigations should continue against them, and dig deep into their background," she said.

"Only when corrupt officials realize that committing suicide will no longer protect their illegal income will they give up the idea."

Zhou, who was a member of the Politburo Standing Committee — China's apex of power- retired in 2012.