The Beijing address is listed in Australian company filings for the pilot and a U.S. blacklisting for the Chinese businessman, however, it was unclear whether they used the Beijing address at the same time.
Australian Federal Police arrested Daniel Edmund Duggan, 54, a former U.S. citizen, in the rural town of Orange in New South Wales state last month, acting on a U.S. request for his arrest.
Details of the U.S. arrest warrant and the charges he faces are sealed, his lawyer said. Consequently Reuters was unable to determine the specifics of Duggan's case.
"He denies having breached any U.S. law, any Australian law, any international law," Duggan's lawyer Dennis Miralis of Nyman, Gibson and Miralis said outside a Sydney court on Friday.
Miralis said Duggan was being moved to a maximum security prison in the regional town of Goulburn and that he did not seek bail at the directions hearing in the Sydney local court. The matter was adjourned until November 28.
A former military pilot told Reuters that Duggan, who became an aviation consultant after his military service, moved from Australia to Beijing in 2013/2014 to work with a Chinese businessman called Stephen.
Shown a photograph by a Reuters reporter, the former military pilot identified Stephen Su, the Chinese businessman convicted on hacking charges in the United States, but did not supply details about the business the two were involved in.
Duggan's LinkedIn profile also said he was in China during this time.
Another aviation source said Duggan went to Beijing to work with Stephen Su, also known as Su Bin in China.
Su Bin was arrested in Canada in July 2014 and jailed in the United States two years later, in a high-profile hacking case involving the theft of U.S. military aircraft designs by the Chinese military in which he pleaded guilty, court records show.
A Reuters review of company filings for Duggan's former business Top Gun Tasmania to the Australian corporate regulator showed Duggan had certified documents that notified of his change of address and his sale of the company in January and April 2014, stating his residential address from December 2013 was an apartment in Beijing's Chaoyang district.
The same address appeared on the U.S. Entity List in August 2014 as belonging to Su Bin and his aviation technology company Nuodian Technology, also known as Lode Tech in English language marketing material.
The U.S. Entity List, which refers to both company names, is a trade blacklist of people and companies deemed to pose a risk to U.S. national security.
The address, Building 1-1, No. 67 Caiman Street, Chaoyang Road, remains on the U.S. blacklist for involvement in the unauthorised exploitation of U.S. Department of Defense contractor computer systems to illicitly obtain controlled technology related to military projects.
When Reuters visited the Beijing address this week the reporter was told it was a residential building and denied entry.
The U.S. blacklist also cites a second address for Nuodian Technology and Su Bin, in an office complex next to the residential building. Reuters was told by a building manager someone from Nuodian Technology had opened an office there, but added the company moved out seven to eight years ago. This is around the time of Su Bin's arrest.
Chinese company records show Nuodian Technology first registered a Beijing office in 2003.
Su Bin, 51, was sentenced to a 46-month prison term in 2016 by a Los Angeles court after being charged with taking part in a years-long scheme by Chinese military officers to obtain sensitive military information.
Su Bin pleaded guilty to conspiring with two Chinese air force officers who hacked into the computer systems of Boeing and other companies to obtain data about military projects, violating the arms export control act.
Duggan arrived in Australia from China weeks before his arrest and had interacted with Australian intelligence agencies, his lawyer said. He did not name the agencies, provide details on what was under investigation or Duggan's possible role in it.
Miralis said he would lodge a complaint with Australia's inspector-general of intelligence, an oversight body, about matters which touch on Australia's national security. The inspector-general's office declined to comment.
Miralis said the United States should not make an extradition request until this complaint was resolved.
Under Australia's extradition treaty with the United States, an extradition request must be made within 60 days of arrest.
"It's important to understand the legal system in Australia has not yet seized jurisdiction of the matter, we are more in the area of international relations, and it is a decision for the United States State Department to determine whether or not it wishes to send an extradition request to Australia," said Miralis.
"This has nothing to do with law, this has everything to do with international politics and international relations."
The United States Department of Justice has declined to comment about Duggan's case.
Australia's Attorney General's Department said it could not give details of any possible extradition request and China's foreign ministry said it was "not aware of this situation", in response to Reuters written questions.
Robert Anello, the lawyer who represented Su Bin in the 2014 hacking case, declined to comment and Su Bin could not be reached for comment.
Duggan's arrest came the same week Britain warned dozens of former military pilots to stop working in China or face prosecution by the British government on national security grounds under new laws to stop former RAF pilots training the Chinese military, because it risked the transfer of secrets and information about British air force capabilities.