Non-government group Safeguard Defenders alleged Beijing had clandestine officers operating in Sydney that collaborated with police in China to harass, threaten and intimidate dissidents.

ASIO head Mike Burgess said he hadn’t seen evidence of operations in Sydney.

“Not that I’m aware of,” he told senators on Monday when asked if there were Chinese police officers working out of Sydney.

“I see many things in the media but I let the data we have available to us to determine that.”

He said he would not comment on specific operations.

“We will investigate things that are associated with acts of foreign interference, but I won’t bring colour to them in a public hearing,” he said.

“If there was anyone here who was engaged in acts of espionage or foreign interference that would be of concern and something that we would investigate.”

Burgess said while espionage has become the agency’s chief issue, he’s not aware of any spy balloons over the country as seen over North America in recent weeks.

Burgess said balloons were not the typical method foreign adversaries used for spying.

“I’m aware of the reporting around balloons and balloons allegedly being used for spying,” he said.

“My experience is that’s not the principal means which by people are spying on this country.”

-AAP