Former Gunns boss John Gay should not have to pay any money in his proceeds of crime case because he did not make a profit, his lawyers argue.

The former chairman of the now collapsed company was convicted in 2013 of insider trading and fined $50,000 for selling Gunns shares in 2009 when he had price-sensitive information.

The Commonwealth Director of Public Prosecutions (DPP) is seeking to recoup the money Mr Gay made from the sale.

Mr Gay's lawyers argue the former timber boss made a loss on Gunns shares he sold with price-sensitive information and that he had already been punished for insider trading.

But the Crown argues while Mr Gay did not make a profit based on the original price of the shares he still had an advantage and lost less than those who were not privy to the information.

In April, Justice Stephen Estcourt rejected the DPP's submission that the amount pursued should be the gross proceeds of the sale, about $3 million.

Today lawyers for Mr Gay said he made a loss when he sold the shares.

The crown estimates he made about $600,000 by selling the shares in December 2009, rather than the following February, when lawyers argued they would have been lawfully sold.

The crown further argued the offence was selling the shares while in the possession of insider information, regardless of the financial outcome.

Mr Gay was fined $50,000 and banned from running a company for five years - a penalty he successfully challenged last year.

Gunns went into voluntary administration in 2012, with investors losing an estimated $1 billion.

Justice Estcourt is expected to make a decision on the case on Tuesday, and parties may be ordered into mediation.