"We have had tens of thousands of refugees come to Australia over the last decade or so and a very few of them have become subjects of interest for ASIO and have been involved in terrorist planning," he told ABC radio.

ASIO chief Duncan Lewis. Credit:Andrew Meares

"I'm not denying that. I've not said that there are no terrorists who have not been refugees or who have not been the sons and daughters of refugees born in this country.

"But the context is very important. The reason they are terrorists is not because they are refugees but because of the violent, extremist interpretation of Sunni Islam that they have adopted."

Following his responses to Senator Hanson last week, the senior public servant was criticised by One Nation, conservative commentators and former prime minister Tony Abbott, who suggested ASIO was "tiptoeing around this subject".