A US federal grand jury indicted a 28-year-old former physics doctoral student on Wednesday in the June 9 kidnapping of visiting Chinese scholar Zhang Yingying.

Brendt Christensen, 28, of Champaign, Illinois, who has a master's degree in physics from the University of Illinois at Urbana-Champaign, was arrested on June 30 on a charge of kidnapping Zhang, 26, who was attending the same school.

On July 5, he was ordered held without bail by US Magistrate Judge Eric Long of the US District Court for the Central District of Illinois in Urbana. Christensen will be arraigned on July 20 in Urbana, and his lawyers have said he will plead not guilty. If convicted, he faces a maximum penalty of life in prison.

Zhang, who had been in the United States for about a month, was conducting research at the university and living in university housing. She has not been found, and police believe she is no longer alive.

On June 9, Christensen was driving a black Saturn Astra, captured by security cameras, in Urbana at about 2 pm, an affidavit states. Zhang can be seen getting in the front passenger seat.

She had sent a text to a prospective landlord saying she was on her way to Urbana to sign a lease on an apartment, but she never showed up. Her last phone activity was at 1:39 pm, saying that she was running late and would not arrive until around 2:10 pm.

Wang Zhidong, a lawyer representing Zhang's family members, said on Wednesday that they are "extremely anxious and pained" and asked for help to find Zhang as soon as possible.

"Members of Yingying's family feel comforted by the indictment by the grand jury and express gratitude for the unremitting efforts of the police and prosecutors. They also want to thank people in China, the US and everywhere else for their concern over Yingying," Wang said.

The Federal Bureau of Investigation and police are continuing the investigation.

Zhang Ruinan contributed to this story.

wanglinyan@chinadailyusa.com