A campaign is underway to free a woman jailed for cannabis supply, after drugs were found when her husband called police to a home invasion.

Kaikohe mum and community leader Kelly van Gaalen was jailed for two years this week after being found guilty of possession for supply.

Last July her husband was attacked in his home by three armed men and called police.

Officers at the scene found 684 grams of cannabis, which Mrs van Gaalen maintains was for her own use and to give away to friends, not for supply.

Her case is being appealed.

Julian Crawford from The Cannabis Party has started a petition for her to be freed, and for sentences for cannabis offences to be reduced.

"I'm hoping to present that [petition] in parliament, calling for lighter sentences for cannabis offences and also considering a pardon for Kelly."

He believes there is a lot of inconsistency with sentencing around this issue in New Zealand.

"It seems like a very harsh sentence and the problem in New Zealand is there's a lot of inconsistency with the judges giving out sentences - some of them very lenient and others very harsh like in this case."

Three men have been jailed over the original home invasion.