A trove of documents sourced by multi-award-winning investigative journalist, Nick McKenzie, has exposed a bribery syndicate in the oil industry with links to ministers and officials in Nigeria, Iran, Iraq, Syria, Azerbaijan, Algeria, Malaysia, Libya and Kazakhstan.

It all began with a mysterious typed letter in the mail instructing a multi-award-winning investigative journalist to place a coded message in a French newspaper.

Nick McKenzie had no idea his response would lead him on one of the largest ever international bribery investigations into the oil industry.

He would uncover a trail of crime and corruption and expose one of the biggest family-owned companies in the world – Unaoil.

His journey has been archived in the new feature-length documentary ‘Revealed: Bribe Inc.’ that is now streaming on Stan.

McKenzie told Daily Mail Australia the explosive investigation has all the hallmarks of a Hollywood film.

‘I think it is something that could be a great film, because it has the qualities to it,’ he said.

McKenzie had just helped to smash open bribery allegations at Australian engineering giant Leighton Holdings (now CIMC) when he received the letter.

The missive claimed to be from a former Unaoil employee only known as ‘Figaro’ and asked him to place an ad, including his email address and the code word ‘Monte Christo’, in the real estate section of French newspaper Le Figaro.

‘If you want to get the biggest corruption story in the world, hide a secret code in a French newspaper,’ McKenzie was told.

McKenzie said he followed the instructions and this started his incredible journey.

‘You wouldn’t believe it, if you read it,’ he said. ‘It remains the craziest way of ever being contacted’.

From the outside, the Ahsani family’s Monaco-based company Unaoil had a highly respected reputation – hosting glittering fundraisers and mixing with royalty, politicians and politicians.

The family had created the illusion of being generous and above reproach and had long denied any involvement in corrupt activity.

‘Superficially, the Ahsani family looked like wealthy philanthropists who had years of dealing with royals and sheikhs and people to be respected and admired,’ McKenzie said.

‘It was all a front. I think as the more corrupt they got, the more they painted themselves as not corrupt.

‘This charity they set up, and the way that they moved across high society in Europe, and especially in Monaco, it was all a front.

‘And ultimately they are corporate gangsters.’

He said he was contacted by the whistleblower Figaro because, ‘he’d read that I had written about Leighton Holdings and its involvement in alleged corruption’.

‘He thought, “Who’s going to pay attention to the hidden part of that story, which is the allegation that the bribe payer working for Leighton Holdings was in fact Unaoil”,’ McKenzie said.

This unleashed the greatest exposé of bribery and corruption in modern history.

Delving into the business dealings of the secretive Ahsani family, and armed with  317,000 leaked files, McKenzie and Figaro discovered Unaoil had paid multi-million dollar bribes to some of the biggest companies across Europe, North America and Australia.

The documentary reveals how McKenzie and Figaro tracked down the money trail and chased down the criminals in an exhaustive manhunt spanning the globe from Iraq to Monaco, Rome, London, Australia, and the U.S.

According to the thousands of leaked emails, Unaoil was running a vast network of mysterious middlemen with a hotline to ministers and oil officials in Iran, Iraq, Syria, Azerbaijan, Algeria, Malaysia, Libya, Kazakhstan and Nigeria.

‘Once the data began to flow and once we started document after document, and then a lot more data in the form of a hard drive, then it really, really opened up,’ McKenzie said.

‘It was a really interesting journalistic experience, we spent 18 hours a day, basically poring through emails.’

‘The whole picture began to be painted.’

‘It was extremely exciting, because, you know, you felt like you were cracking a code, and you felt like you were exposing real and genuine major corruption.’

‘It remains the biggest and most complicated investigation, because there was so many files, so many bribes paid in so many countries.

‘I think in the end, the FBI said there was, I think, bribes paid in up to 27 countries,’ McKenzie said.

The documentary even features a cameo from President-elect Donald Trump.

The investigation eventually involved the US Department of Justice and the FBI, and triggered a $12million police investigation as authorities worked tirelessly to bring the Ahsani family to justice.

‘Revealed: Bribe, Inc.’ is the eleventh in Stan’s Revealed series and the fourth fronted by McKenzie.

The multi-Walkley award winner had previously produced Ben Roberts-Smith: Truth On Trial, Trafficked and Amongst Us: Neo Nazi Australia for Stan.

On Tuesday night, McKenzie won three more Walkley Awards, including the coveted Gold Walkley, Australian journalism’s highest honour.

Mailonline