A community leader has called on Chinese parents with children studying in the United States not to overreact about the alleged kidnapping of Zhang Yingying, a visiting scholar who went missing in June.

Simon Pang, president of the US Sino Friendship Association, said the incident had concerned Chinese people - and Asians generally - but stressed it was an isolated case.

The Asian community has been actively involved in the case, he said. "Even Henry Chang-Yu Lee (one of the world's foremost forensic scientists) has been involved. I was also involved, making comments, making suggestions," he added.

Zhang, 26, who was on a study program at the University of Illinois at Urbana-Champaign, has not been seen since June 9, when a campus security camera recorded her getting into a dark-colored car near a bus stop.

Prime suspect Brendt Christensen, 28, of Champaign, was indicted this month on a charge of kidnapping and pleaded not guilty. He will stand trial on Sept 12.

Based on the evidence collected, police say they believe Zhang is no longer alive.

People of Chinese origin living in the US have made efforts to look for Zhang and closely followed the case.

Still, Pang pointed out that "in every country you travel there are good people and bad people". Concern over security is not a good reason to miss out on opportunities to study or work in the US, he added.

He said the Chinese consulate in Los Angeles is doing a good job of protecting Chinese students by "working very closely with Chinese student bodies to make sure everybody stays safe" and by sharing its emergency contact numbers.

Pang is leading a delegation of elected officials from California, including five mayors and entrepreneurs, to China. The trip is scheduled to take them to Beijing and then to the provinces of Sichuan, Fujian and Guangdong.

It is the sixth time his association has worked with the Chinese People's Association for Friendship with Foreign Countries to arrange such a trip.

"Some US reports about China are very negative, so we like to invite elected officials and local mayors to visit China, so at least they can see that China is very different from what is reported," Pang added.