Australia’s top prosecutors knew a controversial letter they wrote in support of besieged NSW chief prosecutor Sally Dowling would be leaked to the media, with Commonwealth DPP Raelene Sharp KC identifying NSW Attorney-General Michael Daley’s office as the leaker, previously secret emails and texts reveal.

The correspondence, released under Freedom of Information laws, shows how the Directors of Public Prosecution for the commonwealth, states and territories banded together to send a letter that was leaked to The Sydney Morning Herald hours before the release of a NSW parliamentary inquiry report that found Ms Dowling had lied to it.

The tranche of documents ­reveals that despite claims the ­letter was simply a private ­message of support for a colleague, behind the scenes the DPPs were expressing anger at what they considered “terrible” treatment by the inquiry and were aware their intervention would be made public.

Ms Dowling thanked the DPPs for the letter, which she said had been “extremely important in the public discussion”, suggesting she too regarded its primary ­function not as a private vote of confidence to Mr Daley, but as a powerful weapon in swaying ­public opinion ahead of the ­report’s tabling.

The complex operation to gather the support of directors across eight jurisdictions was primarily orchestrated by Ms Sharp, in an exercise later approvingly described by ACT DPP Victoria Engel SC as “herding the cats”.

The Commonwealth DPP first wrote to her state and territory colleagues on June 24 claiming “alarming allegations” had been put to Ms Dowling in the inquiry “that she has been lying to the inquiry for a number of months based on (it seems to me) a misinterpretation of her evidence”.

The inquiry had been investigating how a member of Ms Dowling’s staff leaked information to Radio 2GB about District Court judge Penelope Wass, who had been critical of Ms Dowling for bringing baseless rape cases before the courts.

All the directors agreed to sign the letter to Mr Daley, describing Ms Dowling as “a person of integrity who, in our dealings, has always conducted herself in an exemplary and ethical manner”.

The emails between the DPPs in response to Ms Sharp’s request include a scathing comment, likely to embarrass some of the participants, about Federal Court judge Ian Jackman, who in a speech had accused Ms Dowling of using the NSW Judicial Commission to settle a score with District Court judges who criticised her office for prosecuting hopeless rape cases.

Tasmanian DPP Daryl Coates SC responded to Ms Sharp agreeing that “Sally has been terribly treated. The committee ambushed her with Judge Wass’s allegations and completely changed the nature of the inquiry. She has also been regularly attacked by News Ltd.”

Mr Coates then referred to Justice Jackman’s “attack” on Ms Dowling over her Judicial Commission complaints, suggesting the judge must have been ignorant of the regulator’s decisions upholding some of Ms Dowling’s complaints, and saying: “He obviously hasn’t read the findings.”

Other DPPs chime in with their support of that sentiment, with Acting Northern Territory DPP Pat Williams, saying “I echo Daryl’s thoughts” and Ms Sharp agreeing with both.

Ms Sharp sent a text message to Ms Engel, then on holiday in Bali, asking if she wanted to join in signing the letter. The ACT DPP agreed, asking: “Are we doing it knowing likely leaked? I assume there must be a good chance of it.”

Ms Sharp responded: “Yes. We have drafted it on that basis.”

Ms Engel: “Perfect (laugh emoji). Assumed so but always best not to assume I’ve learnt (grin emoji).”

On July 12, five days after the parliamentary report was tabled, the Commonwealth DPP told Ms Engel in another message that the letter “was leaked almost immediately by the AG’s office it seems”.

The revelation that Mr Daley’s office was responsible for the leak is particularly remarkable in light of the Attorney-General’s claims that the inquiry’s findings were a “stitch-up”, and his repeated accusations against the inquiry of “political interference”. Mr Daley did not respond to The Australian about whether he or anyone from his office leaked the letter.

NSW Labor MP Stephen Lawrence, who sat on the parliamentary inquiry, told The Australian the DPPs had “conspired together to craft a dishonest document”.

“I say dishonest because it was disguised as a private letter, but the secret messages show they did it knowing it would be leaked, that makes it a public statement. A public statement they could never have properly made and they knew it,” Mr Lawrence said.

“It was also dishonest in that it disingenuously disavowed being a ‘comment on the evidence’ but the emails show it was exactly that, indeed the statement was conceived because Raelene Sharp didn’t agree with the allegations being put to Sally Dowling.”

Mr Lawrence said there was no evidence the signatories had properly understood the evidence heard by the inquiry, or that they had properly discussed it.

“No amount of sophistry by good lawyers can change what this was, a public statement intended to back in a powerful mate at a key time, using all the authority of their public offices to directly interfere in a political controversy over alleged misconduct,” he said. “They should all hang their heads in shame.”

The correspondence suggests the directors initially baulked at writing a letter, possibly for fear of being seen to interfere in the parliamentary process, but then went ahead anyway.

The emails make it clear that Ms Sharp actively consulted the deputy secretary of the federal Attorney-General’s Department from the outset on the wording of the letter, and that the deputy secretary had warned that an early version “might be seen to suggest the (NSW) AG should take action”.

Two days after sending her first email to the DPPs, Ms Sharp sent a text message to an unidentified person saying: “Having a quick chat with the other directors re Sally … consensus is we cannot write, but want to explore what we can do.”

An early draft of the letter stated: “We have read the material before the inquiry. It has not altered our view.”

Victorian DPP Brendan Kissane KC objected, noting that while he had read only the latest transcript, the draft suggested all signatories had read the entirety of the inquiry materials.

The line was amended to read: “We are broadly aware of the issues behind the questions asked of Ms Dowling and the allegations that have been made. Our opinion of her remains unaltered.”

At least two DPPs expressed gratitude that the edit “relieves us of the task of reading everything”.

The group appeared to be nervously tracking fallout in the aftermath of the letter’s release, with Ms Engel facing heat in an ACT estimates hearing about her role in the letter. On August 4 Ms Engel reported back to the group with a “heads-up” that she had been asked “some pointed questions” in the hearing and that “my response was along the lines that a) my intention was to express support for Sally as a colleague and speaking to my professional interactions with her and b) declined to be drawn into my thoughts on the inquiry or next steps”.

Ms Sharp thanked her for “the very helpful update”.