A Melbourne judge has shown mercy to a couple who scammed $17 million from the woman's employer, giving them lesser jail terms because of their two young daughters.

Key points: The couple sent 428 false invoices for legal fees to insurance underwriter Dual, where Josie Gonzalez worked

The couple sent 428 false invoices for legal fees to insurance underwriter Dual, where Josie Gonzalez worked The fraud was discovered when Ms Gonzalez went on maternity leave

The fraud was discovered when Ms Gonzalez went on maternity leave The judge acknowledged the couple's imprisonment would be difficult for their two daughters, aged six and 11

Josie Gonzalez, 45, has been sentenced to 9-and-a-half years in prison for being the "mastermind" of a scheme which defrauded her employer, insurance underwriter Dual, over a period of more than two years.

Her husband, Alvaro, 51, has been jailed for 7-and-a-half years.

The court heard the couple sent 428 false invoices to Dual, claiming they were for legal fees.

The amounts of the invoices increased as time went on and totalled just over $17.4 million.

Ms Gonzalez was the national claims manager at Dual and forwarded the fake invoices to the accounts department with instructions on how to process them, with the aim of covering up the fraud, the court was told.

A law firm with no office and no clients

The scam began not long after Ms Gonzalez started working at the firm in late 2010, when Alvaro Gonzalez set up a legal firm called Jaag Lawyers which the court heard was "a law firm in name only".

"There was no office, and it had no clients," County Court Judge Paul Lacava said in sentencing.

"It was formed as part of the joint criminal enterprise with the sole purpose of defrauding Dual."

Judge Lacava said the fact both Josie and Alvaro Gonzalez were lawyers was an aggravating factor in their "prolonged" offending.

The couple bought a house in Kew for more than $4 million, the court heard.

They spent almost $470,000 on "living expenses" from May 2011 to June 2013, the judge told the court.

"I conclude that you both lived very well on the proceeds of your crimes," Judge Lacava said.

The couple repaid the money after Dual mounted civil action.

"The money was not paid with regret, nor an apology for your actions," Judge Lacava told Ms Gonzalez in sentencing.

The fraud was only discovered when Ms Gonzalez went on maternity leave in 2013.

An employee thought the invoices were suspicious and did a check on Jaag and found the Gonzalezes as the company directors.

During the trial earlier this year, Ms Gonzalez had tried to claim the invoices were legitimate.

The couple bought a home in Kew for more than $4 million with the proceeds of their fraud. ( Website: RealEstateView )

She claimed she had an agreement with Dual Asia Pacific boss Damien Coates to provide an in-house claims service at Dual and also provide legal services.

The court heard she had pitched such a deal but it was rejected by Mr Coates because he saw a conflict of interest.

"He liked you and respected your work and work ethic," Judge Lacava told Ms Gonzalez.

He said the fraud was "able to succeed for as long as it did because of [Ms Gonzalez's] breach of trust".

Judge describes Ms Gonzalez's evidence as 'sheer nonsense'

Ms Gonzalez was the "mastermind and principal perpetrator of the fraud," Judge Lacava said.

"Your evidence was sheer nonsense. In my view it was a concoction of lies."

The court heard she had defrauded another employer when she was 22 years old, creating Myer vouchers based on falsified customer returns, totalling $24,000.

There was "remarkable similarity" between that offending and the Dual fraud, the judge said.

Judge Lacava took into account the couple's young daughters, aged six and 11, when calculating the sentence.

He acknowledged that having their parents in prison would "doubtless be very difficult" for the children and the extended family members who will need to look after them.

As a result he considered "some measure of mercy" appropriate, particularly for Ms Gonzalez.

Ms Gonzalez must serve at least seven years in prison.

Mr Gonzalez must serve five years before being eligible for parole.