Bankrupt mining magnate 'Diamond' Joe Gutnick paid his wife Stera Gutnick $285,000 a year to work "a few hours a day" as a trainee jewellery designer at Merlin Diamonds, while her husband earned just $45,000 a year as the company's chairman and chief executive.

Details of the remarkable pay arrangement came to light during Federal Court examination by Joseph Gutnick's bankruptcy trustees on Monday.

Mrs Gutnick told the court she reported to her husband, who worked longer hours in the company. She said her primary duties as a $285,000 a year executive were "studying jewellery design" and "accompanying my husband to events".

Mrs Gutnick's bankruptcy trustees are chasing an estimated $200 million of assets that are believed to have moved offshore to parties associated with Joseph Gutnick and his family.

Mrs Gutnick told the Federal Court she could not explain how she came to be owed $33.5 million by her husband.

Mrs Gutnick also admitted under oath she signed hundreds of documents for a web of companies and trusts without ever asking her husband or his lawyers what they were for.

"I trust my husband. The finances are up to him," Mrs Gutnick told the court.

Mrs Gutnick was read a lengthy list of Gutnick family companies and trusts that she is either a company director, guardian or beneficiary of. She repeatedly told the court that she did not know what those companies did, and had little if no familiarity with their daily business.

As revealed by Fairfax Media last year, Mr Gutnick's statement of affairs shows he owes his creditors $275 million, and has no other assets except for $16,087 in savings and a worthless portfolio of shareholdings.

Mr Gutnick declared himself bankrupt in July last year, ahead of a court hearing to hear a petition by his former business partner Indian Farmers Fertiliser Cooperative (IFFCO), which was seeking to have him declared bankrupt over a $54 million debt.

Lawyers for the bankruptcy trustees challenged Mrs Gutnick, and suggested the shuffling of directorships and her taking on a $33.5 million debt were part of a "broader plan to protect Joseph against bankruptcy"'.

While the loan to Mrs Gutnick dates back to July 2000, she claimed "I wasn't aware of it then."

Asked when she first became aware that her husband owed her $33.5 million, she replied "I first knew of it in 2016".

Asked who told her of the debt, she replied "Joseph did" and added "he told me it was a loan on paper and it doesn't mean practically I was going to get it".