It can now be revealed that two companies owned by the Reserve Bank of Australia, Securency and Note Printing Australia, were fined a record $21.6 million in 2012 for their criminal conduct.

However, the cases against four accused individuals have collapsed after bungling by law enforcement agencies.

The lifting of long-standing suppression orders which for seven years cloaked the Securency case in secrecy enables the public to learn for the first time that two Reserve Bank of Australia companies pleaded guilty to bribing overseas officials to win bank note printing contracts.

Until today, the existence of the suppression orders themselves was also not to be published so no aspects of the case could be revealed.

But the resolution of the scandal leaves a mixed scorecard for the Australian Federal Police and prosecutors, with eight guilty pleas, but the collapse of four other prosecutions in the High Court this month over serious procedural errors.

The final act in the prosecution of banknote firms Securency and Note Printing Australia was a guilty plea by former banknote executive Christian Boillot in the Victorian Supreme Court this week.

Boillot’s plea paved the way for the lifting of suppression orders that have prevented the Australian public from being informed about progress of the bribery prosecution, which began in 2011, was argued all the way to the High Court, and cost the taxpayer millions.

Most notably, Securency and NPA pleaded guilty in 2012 to bribing, or conspiring to bribe, foreign officials in Indonesia, Vietnam and Malaysia in order to secure banknote contracts, and the companies, whose boards were overseen by senior RBA officials, paid record fines under proceeds of crime legislation.

These historic guilty pleas had the companies hit with a record Australian proceeds of crime penalty of $21.6 million. Despite the guilty plea and massive fine, no directors of Securency or NPA – which included former senior RBA officials – were ever investigated by Australia’s corporate regulator ASIC for alleged breaches of the Corporations Act.

The RBA said in a statement this morning that its companies had entered guilty pleas at the earliest opportunity. Governor Philip Lowe said: “The RBA accepts there were shortcomings in its oversight of these companies, and changes to controls and governance have been made to ensure that a situation like this cannot happen again.”

The RBA statement also said the Commonwealth Director of Public Prosecutions had accepted the boards of Securency and NPA had no involvement in, or knowledge of, the bribery.

Prosecutors were only presenting cases for breaches of Australia’s foreign bribery laws, not breaches of the Corporations Act.

Individuals to enter guilty pleas to bribery or false accounting offences include Securency managing director Myles Curtis, former sales executive Cliff Gerathy, former finance boss John Ellery and one-time Indonesian agent Radius Christanto.

The RBA accepts there were shortcomings in its oversight of these companies, and changes to controls and governance have been made.

Reserve Bank of Australia Governor Philip Lowe

Despite the guilty pleas, not a single person charged in Australia has been sentenced to jail for crimes which can attract up to 10 years imprisonment.

In the UK, former senior Securency sales boss, Peter Chapman, spent months in jail after being found guilty in 2016 of authorising $205,000 in bribes to a Nigerian mint official to secure banknote contracts.

ASIC has never explained why it failed to act on a police referral of alleged breaches of the Corporations Act by certain former Securency and NPA directors. This left it to the media, parliamentary committees and individual MPs such as Liberal MP Tony Smith and Greens MP Adam Bandt to provide scrutiny.

The Age is now also free to report a serious blunder involving the Australian Criminal Intelligence Commission (ACIC) and the Australian Federal Police in the early stages of the investigation which led to the High Court this month ordering a permanent stay on charges against four other former banknote executives.

The court found that the ACIC had acted “unlawfully” when it used its special coercive powers to help AFP investigators question the four suspects, giving the prosecution an unfair advantage in the case.

Under its coercive powers, ACIC can force a suspect to answer questions or face prosecution. In this case, several banknote executives suspected of involvement in bribery had exercised their legal right not to answer questions by Federal Police.

“The ACC [as it was known at the time] had not conducted a special investigation into the matters the subject of the AFP investigation,” a statement by the High Court noted. “[The ACC] acted at all times simply as the facility for the AFP to cross examine the appellants under oath for the AFP’s own purposes.

“The prosecution … derived a forensic advantage, which the examinations were expressly calculated to achieve, of compelling the appellants to answer questions that they had lawfully declined to answer and thereby locking them into a version of events from which they could not credibly depart at trial.”

The High Court’s unanimous decision is a bitter blow for law enforcement authorities and Commonwealth prosecutors, who have grappled with the complexity of Australia’s foreign bribery laws for years to keep the landmark case alive.

The Securency scandal has become a leading case study for those advocating for a national integrity commission, including independent MP Cathy McGowan.

The case has also been a catalyst in the push for Australia to introduce whistleblower protection laws in relation to financial crime, with the two key whistleblowers who brought the banknote bribery scandal to life, former Securency sales executive James Shelton, and former NPA company secretary, Brian Hood, sacked after raising questions.

Both men said on Wednesday that putting their careers on the line to report corruption had been an extremely difficult experience, particularly with the length of the court case and suppression orders.

Mr Hood said it had been hard to get employment in the corporate sector because the suppression orders prevented the public from knowing his decision to blow the whistle had been vindicated by guilty pleas.

Both he and Mr Shelton remained bewildered that no RBA official or director of the banknote firms had been held to account for the widespread bribery that occurred on their watch.

Mr Shelton said he was staggered the case had taken this long to conclude and that protections for whistleblowers in the corporate sector remained virtually non-existent even though more than 10 years had passed since he began raising bribery concerns at Securency.

“But I’d do the same again. I don’t regret. You see serious criminal conduct and you can’t just walk past it,” he said.

Australia’s first prosecution of any person or company for the offence of foreign bribery came after Federal police and the Reserve Bank failed to adequately act on whistleblower concerns. A taskforce was only launched after revelations in The Age in 2009 which detailed multi-million-dollar payments made by Securency and Note Printing Australia to politically connected middlemen in Africa and Asia.

The early failures led the AFP to overhaul its approach to tackling foreign bribery and appoint a new senior investigator to manage the investigation, Rohan Pike. Mr Pike, who is no longer with the police and runs his own anti-corruption advisory business, said the convictions were an important first for Australia.

They showed police could investigate complex corruption cases when given proper resources, training and leadership. Mr Pike, who received a commendation from the AFP Commissioner for his foreign bribery work, said there was merit in Australia having a “stand alone” fraud agency, such as the Serious Fraud Office found in the UK and New Zealand.

The scandal badly damaged the RBA’s reputation at home and abroad. So prominent were some of the alleged overseas targets of the companies’ bribery that the Department of Foreign Affairs and Trade successfully sought a suppression order on the identities on the foreign politicians and officials. They included powerful figures – among them an arms dealer and a suspected spy chief –with connections to overseas prime ministers and presidents.

The suppression order itself became a cause for controversy after it was revealed that one of the names suppressed was that of Indonesian president Susilo Bambang Yudhoyono, even though there was never a suggestion that he had been part of any wrongdoing. Ex Malaysian prime minister Najib Razak was also implicated.

The RBA sold its 50 per cent stake in polymer banknote maker Securency. It still owns and controls NPA.