The text messages between Natasha and the taxi driver on February 12.

A cab customer is calling for new protections to stop taxi drivers from being able to access passengers' private contact details after a driver left her feeling "violated" by messaging her after he dropped her off at work.

The Crown Cabs employee's conduct is now the subject of an investigation by the industry watchdog, with five other women also claiming they had similar experiences with the same driver.

Sunbury nurse Natasha, 31, said she made two cab bookings on February 4 and 10, and the same driver picked her up from her home both times.

She said she was "unsettled" when he asked her personal questions about her rental property but it wasn't until Tuesday, February 12, that she said his behaviour became "really creepy".