Speculation will keep growing until Golriz Ghahraman breaks silence on shoplifting allegations, legal expert says

If shoplifting allegations against Golriz Ghahraman prove true, the value of property stolen will be the key to her future, a legal expert says.

On Monday evening, a third allegation emerged against the Green Party MP.

Police confirmed a report of shoplifting at clothing store, Cre8iveworx, on Wellington's Cuba Street was being investigated.

A Green Party spokesperson confirmed the party was aware police were investigating.

It followed two allegations of theft at Auckland clothing retailer, Scotties Boutique, before Christmas.

Otago University's Andrew Geddis said if an MP was convicted of a crime with a sentence of two or more years imprisonment, they would be expelled from parliament.

He told Morning Report the theft of an item worth more than $1000 carried a jail term of up to seven years, while anything of a lesser value was a term of one year.

"If she were to be convicted of stealing something more than $1000 she would automatically be out of parliament. So partly the question is, has she actually committed an offence? We only have allegations at the moment. Then the question would be, if she has committed an offence, how much is the value of the property she's taken?"

Geddis said the longer it took to hear Ghahraman's side of the story, the more public speculation will grow against her.

"When you only hear one side of a story of course you tend to believe that side that you've heard. We need to hear the other side ... but the longer it's allowed to linger, the harder it's going to be for that other side to get traction."

When asked about whether the waka jumping law could be invoked if the allegations were proven to be true, Geddis said it was purely speculative.

He said if that situation arose, the Greens could kick Ghahraman out of the party and she would become an independent MP unless she resigned from parliament.

"If she became an independent MP, the Green Party would technically have the ability to use the party-hopping provisions of the law to kick her out of parliament if she refused to voluntarily resign."

But he said that could become another problem for the Green Party.

"They were very, very opposed to those measures being adopted in the first place. They actually want to see them repealed. So it would be somewhat hypocritical for them to now rely on them."

Ghahraman was on a planned overseas holiday when the first allegations came to light.

She is now back in New Zealand.