Drug reform advocates are calling for New Zealand's drug laws to be thrown out in response to the case of Kaikohe mother of three, Kelly van Gaalen.

The New Zealander of the Year finalist was sentenced last July to two years in prison before a 'Free Kelly' campaign was launched and her conviction overturned on appeal. She spent three months inside.

This week she received a new sentence of five months community detention and 300 hours community service.

Newshub has been unable to report until now that Ms van Gaalen pleaded guilty to the charge of possession of cannabis for supply at her retrial in Whangarei. The retrial was ordered after she appeared in the Court of Appeal last October.

In her first hearing, Ms van Gaalen pleaded not guilty to the same charge, prompting the two year sentence and nationwide outrage at its severity.

Judge John McDonald, who handed down the original two year sentence also presided over the retrial, this time reducing the sentence to five months community detention.

He did offer to stand aside at the second trial but Ms van Gaalen said she didn't hold any grudges.

"He's only human like you and me."

Ms van Gaalen told the Nation she did not possess cannabis for supply but pleaded guilty because she didn't want the process to drag on.

"I probably would have liked to have fought it to the bitter end, but I don't have the strength to fight this battle, I just need it to end," she said.

Ms van Gaalen's defence lawyer told the Court of Appeal, Judge McDonald made a series of errors in the lead up to the initial sentencing.

Judge McDonald did not allow the defence to present a possible reason for the home invasion, which led to the discovery by Police of Ms van Gaalen's 655 gram stash of cannabis.

Under the current law if a person is found with over 28 grams (an ounce) of cannabis, it's presumed to be for supply.

Ms Van Gaalen's husband Jasper said police and the jury in the case believed that the home invasion, in which he was attacked, was due to Ms van Gaalen running a major drug-dealing operation.

Police also confiscated bags of powder from the fridge which they thought may be filled with methamphetamine. The family said it was sherbet given to the kids by their grandmother.

"I think they thought they'd landed on something huge, they thought they were going to take us down," said Mr van Gaalen.

Ms van Gaalen said the cannabis was only for personal use and the reason she had so much was because the two plants she had been growing had particularly good yields that year.

"I love gardening and at the time they were my pride and joy," she said. Asked by Newshub what she planned to do with that much marijuana she said, "smoke it, keep it, share it".

Chief Executive of the Drug Foundation Ross Bell says Ms van Gaalen's case shows why the laws around drugs should be thrown out.

"The definition of insanity is doing the same thing over and over again expecting a different result and we've tried this for the past 40 years" said Mr Bell.

Mr Bell said the 1975 Misuse of Drugs Act breaks a human right that someone is innocent until proven guilty and this is what happened in the case of Ms van Gaalen.

He added that her original sentence of two years prison was not consistent with other similar cases in which people were found in possession of large marijuana quantities.

In 2013, an Israeli couple in Ashburton was found with 54 plants in a cultivation room and 6 kilograms of dried cannabis. They were discharged without conviction.

Last year Cannabis campaigner, Maki Herbet was given 12 months home detention for the cultivation of 153 plants for supply.

"How is it that a judge in one court can show that degree of compassion, but this guy [Judge McDonald] said no my hands are tied and you're going to jail for two years, so it points to there must be something wrong in that law," said Mr Bell.

Mr Bell believes the case of Ms van Gaalen has spurred a subtle shift in the Government's position toward drugs, with a focus on compassion and proportion.

"Everything in Kelly's case was anything but compassion and proportion," said Mr Bell.

Newshub.