Some immigration IT systems have been brought back online after passengers at international airports across Australia were delayed by a mass outage.
SmartGate passport control machines, which work with e-passports and use facial recognition technology to check travellers' identities, have malfunctioned, requiring passports to be checked manually.
Passengers are being encouraged to arrive at airports early to allow additional time for processing.
The Australian Border Force (ABF) said it was working with the Department of Home Affairs to resolve the outage, which is affecting the processing of inbound and outbound passengers.
"A number of Australian Border Force (ABF) and Department of Home Affairs IT systems impacted by an earlier outage have now been restored," a spokesman said on Monday afternoon.
"The Department is continuing work to bring all systems back online, ensure the integrity of the systems and resolve any ongoing issues."
Passengers queue at Melbourne Airport. Source: Twitter: @DerangedRadio
Photos posted on social media from around 7am Monday AEST showed large queues and crowds waiting in terminals in Melbourne, Brisbane and Sydney. Posts uploaded at around 9:30am AEST indicated queues had built up and were moving slowly.
A spokeswoman for Perth Airport also said their systems had been affected, but had not caused significant delays.
SmartGate technology is fitted at ten Australian airports: Melbourne, Sydney, Brisbane, Adelaide, Canberra, Gold Coast, Perth, Cairns, Darwin and Avalon.
The system was first introduced in 2007.
Additional reporting: Evan Young.
