A two-hour Australian Border Force (ABF) processing system outage caused delays for arrivals and departures at international airports across the country on Friday morning.
The technical outage affected SmartGate kiosks for inbound and outbound passengers at international airports nationwide.
A spokesperson said additional officers manually processed passengers while the devices were down between about 10am and noon.
"The cause of the technical issue remains under investigation," the spokesperson said.
A Sydney Airport spokesperson said it caused delays for passengers at the country's busiest airport.
The technical outage affected SmartGate kiosks and caused lengthy queues at Sydney International Aiport. (Supplied: Thiago Moreira)
Thiago Moreira arrived at Sydney International Airport for his trip to Brazil about 9:30am and said he checked his bags in before being told by staff the system was offline.
He said the line was about 500 people deep about 10:30am and passengers were processed in a very orderly manner.
"The staff are being very honest and up-front about it and taking people who have their flight soon first," he said.
Mr Moreira said after being processed by security, passengers ran to their gates to avoid any further alerts.