Indian couple Pankaj and Radhika Oswal fled Australia when they realised the game was up after skimming money off the top of their fertiliser business, a court has heard. 
The Oswals effectively ran a Ponzi scheme, a fraudulent investment operation, and planned to "sail back to India" at the end of it, US oil and gas company Apache Corporation's barrister, Stewart Anderson, QC, said.
"When they saw the game was up, they left the country in their private jet and let everything unravel," he said.
Mr Anderson said the Oswals hid $US490 million in cost overruns in the construction of the Burrup ammonia plant. ANZ and other financiers were told the price was set at $US320 million, despite Mr Oswal knowing it could cost as much as $US300-400 million more, the Victorian Supreme Court heard on Monday.
Mr Anderson said Apache would have ended its gas supply agreement if it had known about the overruns. He said the only way the Oswals completed the ammonia plant, in 2006, was by hiding the excessive costs.
The court has heard more than $150 million in Burrup Fertilisers' money was spent on the couple's Perth mansions.
The Oswals left Australia in   December 2010, a few days before ANZ appointed receivers to their Burrup business.
They returned in   April this year and want up to $2.5 billion from ANZ and the receivers over the sale of their 65 per cent stake in Burrup Holdings.
They also want damages from Apache, which has a $US400 million counter-claim against the couple.