Chinese authorities have arrested a former University of Iowa student in southeastern China and say they will prosecute him in the killing of his girlfriend in Iowa, where her body was found stuffed into the truck of her car, Iowa City police said.

An Iowa City police news release issued Monday night said Xiangnan Li, 23, surrendered to police in Wenzhou on May 13 and was arrested on June 19 to face a charge of intentional homicide.

Li had returned to China following the slaying of Tong Shao, a 20-year-old Chinese national whose body was found Sept. 26. An autopsy said she'd been asphyxiated and authorities said she had been killed after a weekend with Li at a motel in Nevada, Iowa. Shao was reported missing on Sept. 17 in Ames, where she was an international student at Iowa State University.

Johnson County Attorney Janet Lyness told The Des Moines Register that Iowa authorities want Li to be returned to the U.S. for trial, but that the United States and China don't have an extradition treaty.

"That's the only way we could have him prosecuted -- to have the Chinese do it themselves, because they will not extradite anyone back from China," Lyness said.

The Criminal Investigation Bureau of China said that under Chinese criminal law, Chinese citizens are subject to Chinese prosecution for any crimes they commit abroad. The range of punishments in China for intentional homicide includes the death penalty, life imprisonment and imprisonment over 10 years.

Iowa authorities had said Li was a person of interest in the investigation, but he returned to China before he could be questioned. Iowa City police officials contacted Chinese officials, and soon the Criminal Investigation Bureau of China and police in Zhejiang Province opened an investigation.

Iowa officials said a team of Chinese investigators came to Iowa in early June to join Iowa police and prosecutors in their investigation.

China's Ministry of Public Security said in a statement Monday that Chinese detectives collected evidence, checked the crime scene and questioned witnesses. U.S. police handed evidence to the Chinese team, the ministry said.

Wenzhou is a city in the coastal province of Zhejiang in southeastern China.