One of Australia's most covert spy agencies has exposed itself to the mercy of social media with its very first tweet.

On Monday, an account claiming to belong to the Australian Signals Directorate (ASD) issued a cheeky post to begin life on Twitter.

"Hi internet, ASD here. Long time listener, first time caller."

While the move appears to be timed to coincide with a new focus on transparency at the agency, Twitter users were quick to question the account's veracity.

One asked, "Is this an official account?" which prompted a reply from an account claiming to belong to the ASD's director-general himself, Mike Burgess.

That account is also unverified.

"Yes. Live today," Mr Burgess posted.

"I mean … they could've asked @TwitterAU before setting up the account," wrote Asher Wolf, who does own a verified account.

Later that day, Mr Burgess addressed Canberra's national security community in a speech titled Then and Now - Coming Out of the Shadows, boosting the account's credibility.

The agency's maiden tweet joins an illustrious group of other prominent users who took the step with a tongue-in-cheek first post.

Could not display Tweet

Could not display Tweet

The ASD became an independent statutory body on July 1 this year, when it separated from the Department of Defence and Mr Burgess became its first director-general.

The agency now reports directly to the Defence Minister and has a widely increased brief.

It has also taken on new transparency and reporting obligations, which previously fell to the defence department.

While the declining use of Twitter caused the company's stock to dip by 20.5 per cent in July, this recent endorsement by a government agency suggests the platform may have some life in it yet.

An ASD spokesperson said stepping into the Twittersphere was just the beginning of their strategy to become "more open and transparent".

"ASD will also expand its social media presence over time to include other platforms," the spokesperson said.

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#PutOutYourTweets

Twitter's search function allows users to find the first tweet from a specific Twitter handle.

To do so, users must find the date the account first joined Twitter (listed in the bio field).

Then they can use the following formula to find the first tweet.

from:twitterhandle since:yyyy-mm-dd until:yyyy-mm-dd

So if a user joined in April 2012, the search should be since:2012-04-01 until:2012-04-30.

If no results show up the date range may need to be widened, as the first tweet may not match up with the day joined.

Twitter's advanced search can also be used, and provides fields for specific accounts and date ranges.

Sifting through first tweets can dredge up some interesting results.