National says a lost USB drive, containing information on more than 1000 NZTA employees, is a massive security breach and is calling on the Privacy Commissioner to investigate.
The USB drive was misplaced somewhere between Auckland and Wellington late last year, Transport Minister Phil Twyford confirmed in written parliamentary questions a week before Christmas.
He also confirmed the USB drive was not password protected, nor was it encrypted.
It contained the names and email addresses of 1104 NZTA staff.
National's Data and Cybersecurity spokesman Shane Reti said the misplaced drive constitutes a "significant data privacy breach".
"It is hard to believe, and completely unacceptable, that NZTA would courier staff identity data without password protection and without encryption."