WORCESTER – A federal judge in Worcester Friday ordered a Chinese researcher accused of trying to smuggle cancer cells to China released before trial, denying a request from prosecutors that he delay his order while they appealed.

Zaosong Zheng, 30, had no comment as he walked out of U.S. District Court in Worcester bound for his apartment in Boston, where he will be under GPS-monitored house arrest.

Zheng was arrested in December after authorities at Logan Airport found 21 vials of cancer cells in a suitcase he was taking to China.

The government has opposed his release, arguing that he may be working with the Chinese government and raising questions about the source of $25,000 in additional bail money posted by his wife.

But Zheng has not been charged with conspiring with the Chinese government, and a federal judge Friday denied multiple requests from prosecutors that he remain in jail until an appeal could be heard.

“I wouldn’t be releasing the defendant on these conditions if I did not believe … they would reasonably assure (his) appearance,” Chief Magistrate Judge David H. Hennessy told Assistant U.S. Attorney Benjamin Tolkoff.

Tolkoff moved for a stay of Hennessy’s release order and, when that was denied, asked him to reconsider, saying he believed it possible another judge would rule differently.

In addition to raising questions about the source of bail money, Tolkoff had argued Wednesday that Zheng could face additional charges. He is currently charged with smuggling and lying to authorities.

An FBI agent testified Wednesday that preliminary forensic evidence indicates Zheng had communications with two people in China about the stolen vials, including one person from a university that planned to store the material in China.

Zheng told the FBI he stole the vials for his own research. Prosecutors allege in court documents his conduct "appears to have been a coordinated crime, with likely involvement by the Chinese government, as at least two other Chinese nationals working at the same lab have also stolen biological materials and smuggled them out of the United States."

Zheng’s lead private lawyer, David Duncan, did not directly answer a question from the Telegram & Gazette Friday as to whether his client was working with the Chinese government.

Duncan, who took the question as he left the courtroom with Zheng’s wife, said he does not believe his client did anything wrong, and noted he is still preparing for trial.

Duncan wrote in court documents that Zheng’s wife, Wenjie Zhu, is in the U.S. conducting research at the National Institutes of Health.

Zhu politely said goodbye to a reporter after Duncan declined to make her available for comment.

Norman S. Zalkind, another lawyer who represents Zheng, declined to allow a reporter to question Zheng as he and his defense team left the courthouse after meeting with probation officers.

Zheng was aided at the defense table Friday by a Mandarin interpreter.

Federal authorities have been ratcheting up attempts to go after Chinese theft of research; in addition to Zheng, who was working for Harvard’s Beth Israel Deaconess Medical Center, they have arrested Harvard chemist Charles Leiber on unrelated allegations of setting up a lab in China in exchange for money.

Both Harvard University and Beth Israel requested Friday that Zheng stay away from their campuses. That request was deemed moot in court after Hennessy ordered Zheng on GPS-monitored house arrest.

Zheng, who lives at the Longwood Galleria in Boston, will be required to stay there except for medical and legal calls. He will also be allowed to go grocery shopping.

Hennessy ordered Zheng released after receiving notice from Longwood that Zheng’s family had paid his rent through the end of May. While prosecutors argued he is a flight risk, Hennessy noted the man’s passport has been taken and that his family has posted $40,000 cash toward his $100,000 bond.

The U.S. Attorney’s office did not immediately respond to an email offering comment Friday afternoon.

U.S. District Court Judge Denise J. Casper, the Boston judge who will ultimately hear Zheng’s case, affirmed Hennessy’s denial of the stay late Friday, court documents show.

Casper ordered an expedited schedule for the government’s motion of appeal, requiring Zheng’s lawyers to file a response by March 11.

Contact Brad Petrishen at brad.petrishen@telegram.com. Follow him on Twitter @BPetrishenTG.