Exclusive: Australian travellers returning from the United States on an ESTA waiver are disputing accusations they have illegally overstayed their visa by months or even years.

US immigration appears to have failed to record some outbound Australian passengers on cruises and planes after travelling on an Electronic System for Travel Authorisation (ESTA), potentially exposing a hole in the country's exit checks for foreign nationals.

Lismore man Aaron Drooger's holiday was ruined in April.

READ MORE: Aussie couple's dream holiday ruined over US immigration debacle

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