The statement comes as the US Postal Service made headlines over its Mail Isolation Control and Tracking program, which uses computers to photograph the exterior of every single piece of paper mail that is processed in the US.

The total for last year was a staggering 160 billion photographs of pieces of mail. It is not known for how long the US government saves the images.

The revelation comes as the US government struggles to contain evidence that its National Security Agency has been engaged in widespread spying on its own citizens by monitoring telephone calls and email.

Fairfax Media on Thursday spoke to an Australia Post spokeswoman, who said the same practices were not in operation in Australia.

“Australia Post does not photograph mail,” the spokeswoman said. “The only time Australia Post personnel would ever observe mail articles would be if we were specifically obliged and directed to do so by a law enforcement agency with the appropriate authority. Even then it would not be photographed.”

The practice of photographing, or recording, the covers of posted mail in the US has been around for more than a century, but advances in technology mean the program now collects vast amounts of personal information of senders and recipients every day.

Postal workers record information on the outside of letters and parcels before they are delivered; opening the mail requires a warrant.

But law enforcement can request, without a warrant, details from the outside of mail packages – reportedly the postal service receives about 20,000 such requests a year.

Details of the Mail Isolation Control and Tracking program were revealed in The New York Times on Wednesday.

A former FBI agent was quoted on the benefits and potential concerns about the mail-scanning program, saying the mail-photographing process was “a treasure trove of information”.

“I can see who you bank with, who you communicate with — all kinds of useful information that gives investigators leads that they can then follow up on with a subpoena.”

But he warned that such a system “can be easily abused because it's so easy to use and you don't have to go through a judge to get the information. You just fill out a form.”