Avneesh Sehgal was jailed on Tuesday for his part in selling his girlfriend's teenage daughter as a prostitute.

The Solicitor-General wants a harsher sentence imposed on a mum who kept her daughter as a prostitute and sex slave.

Kasmeer Lata was jailed for six years and 11 months by Justice Matthew Muir in April for keeping her daughter as a sex slave.

She was jailed for dealing in a person under 18 for sexual exploitation, receiving earnings from commercial sexual services from an underage person, and dealing in slaves.

Lata must serve a minimum of three years and five months in prison.

READ MORE: Man jailed after selling girlfriend's daughter up to five times a day as a prostitute

Lata's is one of just three slave-dealing convictions in New Zealand's legal history since the crime was written into the Crimes Act in 1961.

On Tuesday, Crown prosecutor Natalie Walker said an appeal had been filed against Lata's sentencing by the Solicitor-General.

Crown Law lawyer Charlotte Brooke was unable to comment on the nature of the appeal as it was now before the Court of Appeal.

On the victim's 15th birthday, she was forced into prostitution by Lata and Lata's boyfriend Avneesh Sehgal.

The pair told her that the family would be homeless and left to starve if she did not sell herself for sex.

Over the course of 18 months, the victim was sold up to 1000 times, sometimes five times a day.

She escaped her nightmare in 2016 and fled to the police in Whangarei.

On Tuesday, Sehgal​ was sentenced to four years and eight months behind bars when he appeared at the High Court in Auckland.

He had earlier pleaded guilty to three charges of dealing in a person under 18 for sexual exploitation and receiving earnings from commercial sexual services provided by an underage person.

In sentencing Lata, Justice Muir said he had "no doubt that the defendant's actions have caused long-lasting, if not irreparable damage to her daughter.

"The complainant's feelings of betrayal, anger, and anguish are palpable."

Justice Muir said in the sentencing it was appropriate to send a strong message to all parents that New Zealand Courts would not countenance the prostitution of their children, whatever their financial or immigration circumstances may be.

"Such children are entitled to the love, care and support of their parents, not farmed out for financial gain at enormous potential cost of their children's ultimate physical and psychological wellbeing."