Peter Gregg left Leighton in 2011 and went to UGL, also an engineering group, where he stayed until 2013. Both Leighton and UGL were bought out by the Spanish-based multi-national CIMIC, long after Gregg's departure (2015 and 2016 respectively. In 2013, Gregg went to Primary Health Care, a listed company, as CEO where he remained until he was charged with the offences for which he has now been convicted.

The charges were that Gregg "engaged in conduct that resulted in the falsification of books affecting or relating to the affairs of the company." Essentially, it involved fictitious transactions between the company and another called Asian Global Projects and Trading FZE. That company is registered in the free trade zone at Sharjah in the United Arab Emirates. Many on-line directories (which appear to be replicate information from one another) say that that company "sources steel products, scrap, coal, et. and equipments (sic) for its clients in India, KSA [Saudi Arabia], USA." Two payments totalling AUD15m were made under "an agreement to buy and sell between the company and Asian Global Projects and Trading FZE dated 1 August 2011." The agreement was supposed to be for the purchase of steel at a price that made it particularly attractive. However, no steel was delivered. The company looked into the deal after Gregg's departure and reported its findings to the Australian Federal Police in 2011. Then, ASIC stepped in to look at allegations of bribery and corruption during the period 2009 to 2011. It appears that the Gregg case was swept up in an investigation into unrelated matters: there were reports in several Australian business newspapers relating to an oil and gas services company, Unaoil, registered in Monaco. Reports say that Leighton Holdings was a significant beneficiary of Unaoil's dealings relating to contracts in Iraq.