Huajun Zhao, 42, who has been working in the United States since 2006, appeared in court Monday where federal judge ordered him held without bail, the Milwaukee Journal Sentinel reported. He was arrested Saturday.
Zhao could receive as much as 15 years if he is convicted of economic espionage.
The federal complaint said Marshall Anderson, a professor at the medical college in Wauwautosa, discovered in late February three containers of an experimental compound, C-25, were missing from his office. An investigation began and security footage showed that Zhao, who worked for Anderson as a research assistant, was the only person who entered the office on Feb. 22, the day the compound went missing.
After the alleged theft was reported to the FBI, an examination of Zhao's home computer turned up items from Anderson's research.
The investigation turned up evidence Zhao hoped to claim credit in China for discovering C-25. They included a grant application written in Mandarin saying he had discovered the compound, although much of the information was translated from an English application Anderson submitted several years ago.
The college also discovered Zhao, on a research website, said he had discovered a compound he hoped to take to China.
A medical college spokeswoman said researchers are trying to determine if C-25 "can assist cancer drugs in killing cancer cells and not damaging 'normal' cells."