ZDNet has obtained one presentation used by the Australian Federal Police (AFP) in lobbying Prime Minister Tony Abbott behind closed doors for mandatory data-retention legislation to pass.

The Australian government is pushing for mandatory data-retention legislation to pass through the parliament in the final two sitting weeks before the Budget in May.

The legislation will require telecommunications companies to retain all customer communications data -- such as call records, assigned IP addresses, billing information, download volumes, and other so-called "metadata" -- for two years for warrantless access by law enforcement.

The government has accepted all proposed amendments put forward by the Joint Committee on Intelligence and Security (JCIS) late last month, and is expected to introduce the amendments to the legislation in the next two weeks.

Abbott and his government have been attempting to make the case for why it needs the data of every Australian citizen kept on the off chance that it may help in an investigation, but polls show that the public does not yet trust the government on this issue.

Discussing the importance of the Government's data retention legislation pic.twitter.com/1pgmrGmoEY -- Tony Abbott (@TonyAbbottMHR) February 5, 2015

In February, Abbott held a press conference at AFP's Melbourne headquarters, where he expressed the need for the legislation to pass as a result of a private presentation he was given by AFP Commissioner Andrew Colvin.

"I want to say thank you to you, commissioner, and thank you to all of the AFP staff this morning for the briefing that you provided to the minister and myself on metadata and its importance in fighting crime, whether it be child abuse, whether it be terrorism, whether it be fraud, drug importation. Whatever it is, metadata is vitally important -- absolutely critical," Abbott said at the time.

"Now, as we know, technology is changing all the time, and telecommunications companies are not keeping these records for as long as they did. We have, if you like, a burning platform, and as a result of that burning platform, increasingly, police and other crime fighting agencies are going blind.

"That's why we need this metadata-retention legislation. It's an absolutely vital part of the national security legislation that this government has been progressively introducing over the last few months."

Colvin said that metadata is "a basic building block" for investigations, without which investigations would be "severely hampered".

ZDNet has obtained a redacted copy of the presentation under Freedom of Information. The presentation goes through largely the same arguments that the AFP has made to the parliament in the past, highlighting specific instances where telecommunications data has been used to investigate child abuse, terrorism, and organised crime cases.

Mandatory Data Retention legislation presentation

The AFP highlighted Operation Inca, which dealt with 20 shipping containers containing 4.4 tonnes of ecstasy in Port Melbourne in 2007. The AFP accessed 2,000 call records in this case, and used it to obtain intercept warrants. The AFP also used access to telco data such as which SIM was used in which handset, and the time, date, and cell site for calls.

The AFP has, however, not been able to quantify exactly how many cases have been solved using metadata, or how many prosecutions have been obtained. Nor has the AFP been able to explain how needing a warrant would in any way harm its ability to undertake these activities.

It comes as the JCIS will meet this week to discuss the implications of the legislation on journalists and their sources. The legislation does not prevent a government agency from using its power to access a journalist's call records to determine who that journalist has been talking to.

Opposition Leader Bill Shorten has said that Labor reserves the right to amend the legislation to protect journalists, but the data-retention legislation is due to pass before the committee reports back.

The Australian Federal Police refused to confirm whether any journalists have been the subject of telecommunications data requests. ZDNet attempted to extract information about the AFP's history of accessing journalists' telecommunications data under Freedom of Information, but was refused on the basis that revealing whether the AFP has used its power in that way in the past would threaten its ability to access telecommunications data to investigate journalists in the future.