Police brought a civil action under the Crime Proceeds (Recovery) Act to seize Musson's assets.
His wife Lesley Anne Musson, 49, and 74-year-old mother-in-law Anne Maria Hammill were named as co-respondents in the action.
After a hearing at the High Court in Christchurch, Justice Gerald Nation has found that all three profited from Musson's "significant criminal activity" based out of a property in the Christchurch suburb of Bishopdale.
The value of the unlawful benefit Musson obtained from his criminal activity amounted to $795,958, the court heard.
The judge granted the profit forfeiture order for the property, which includes a flat on its grounds where Mrs Hammill lived.
A judgment released today said the property, which has a current value of $495,000, was jointly owned by the Mussons, and Mrs Hammill's equitable interest in the property was worth $107,000.
The judge also made profit forfeiture orders for a 2004 Chrysler Grand Cherokee, a 2009 Briford trailer, and a 1996 Yamaha UMX 1200 motorcycle.
An assets forfeiture order in respect of $5000 cash found at the property was also made.
Justice Nation said the house was a base for Musson's criminal activity.
"Paraphernalia associated with his criminal offending was found at the address when the search warrants were executed on both May 23, 2012 and February 26, 2013. A significant value of prescription medicines were found at the address on both occasions," he said.
The judge found that Musson's wife "had knowledge of what he was doing".
"There is no evidence that she took any steps to try and bring what he was doing to an end," Justice Nation said.
"In terms of the way they lived off the proceeds of his criminal activity and to the extent of the significant discretionary spending on clothes and other fashion items, Mrs Musson personally took benefits from his criminal activity."
He also found that Mrs Hammill also knew of Musson's crimes, benefiting directly through payments she received for helping him fill the prescribed medicine vials.
"She allowed Mr Musson to use her bank account for significant financial transactions when she knew that what he was doing was illegal. In all these ways, to the extent that she was benefiting from his significant criminal activity, Mrs Hammill was putting her interest in the property at risk of forfeiture to the extent that interest reflected the value of the benefits that she had obtained."
The judge was not satisfied that neither Mr or Mrs Musson, nor Mrs Hammill, would suffer any undue hardship if their interests in the Bishopdale property were forfeited.
Musson's original business partner, Chetan Viraj Jethwa was given one year's home detention and 300 hours of community work when he was sentenced in September 2012 in Hamilton.