Bilardi passport cancelled in Oct: Bishop

Alleged Australian suicide bomber Jake Bilardi's passport was cancelled in October last year, Foreign Minister Julie Bishop says.

The Melbourne teenager is believed to have been killed in one of a series of Islamic State suicide bombings across the Iraqi city of Ramadi.

Ms Bishop said if the reports were confirmed it was another tragic example of a young Australian being lured to a "senseless and violent death".

Australian authorities were aware Bilardi travelled to Iraq and Syria in August last year, she said.

"In October on the advice of our security agencies, I cancelled his Australian passport," Ms Bishop said.

At least 20 Australians have been killed in the conflict and 100 passports have been cancelled on national security grounds.