Receivers behind the sale of Pankaj and Radhika Oswals' interest in Burrup Fertilisers ran a "flawed" process and were in effect puppets for the ANZ Bank, a court has heard.

The receivers, from PPB Advisory, are being sued by the Oswals over allegedly selling their 65 per cent stake in the West Australian fertiliser giant on the cheap at the behest of ANZ Bank.

The billionaire entrepreneur and his socialite wife allege they are owed between $1.5 billion and $2.5 billion over the sale of their interests in Burrup Fertilisers.

ANZ called in the receivers over the Oswal's stake in Burrup in 2010. The stake was later sold to Norway's Yara International, which was already a shareholder in Burrup and New York-listed Apache Corp, which had a gas supply agreement with Burrup for a total price of $US560 million.

Lawyer for the Oswals, Tony Bannon, SC, told the court the sale process undertaken by PPB gave preference to Yara, which held a stake in Burrup.

"We say that there was an impossible conflict," Mr Bannon said.

Mr Bannon said to appease Yara's desires to get a slice of the Oswals' assets the receivers decided to give preference to Yara and Apache in the deal.

"We say that the steps they took didn't pay regard to the interests of the Oswals," Mr Bannon said.

Mr Bannon told the court PPB was acting as a "puppet" for ANZ.

"The receivers were essentially acting as agents for the ANZ," Mr Bannon said, adding that Yara was allowed an "undue influence".

Mr Bannon also told the court the sale process failed to take into account the enormous financial benefit Apache received from its inclusion in the deal.

As a result of the deal, Apache was able to renegotiate the gas sale agreement with Burrup on much more favourable terms, the court heard.

The trial, in the Supreme Court of Victoria before Judge Julie Dodds-Streeton, is expected to take three months.

On Monday, the court heard Mr Oswal had signed a guarantee over his shares to the ANZ for $900 million under duress, claiming he was placed in a headlock by an ANZ senior executive and forced to sign the guarantee.

Separately, Mr Oswal is alleged to have taken more than $150 million for personal use on private planes and other luxury goods from entities associated with the fertiliser plant.

Mrs Oswal, a vegetarian lifestyle evangelist, has also been accused of dodging a $186 million tax bill issued by the Australian Taxation Office.

After arriving in Perth in 2005 to much fanfare, the Oswals built Burrup into a major force in the West Australian mining scene.

They ploughed millions more into their expansive residence in Perth's ritzy suburb Peppermint Grove, dubbed the "Taj on the Swan" by locals.

The Oswals left Perth in 2010 after receivers were appointed, abandoning their half finished pile which this year the local council ordered be demolished. They also left behind a tangle of legal battles.

The couple, who have been based in Dubai since leaving Perth, deny any wrongdoing.

The trial continues.