"Green fairy" Rose Renton is having her Kiwibank account shut down less than a year after the same bank awarded her a "local hero" medal.

Renton has been a prominent campaigner for medicinal cannabis since the death of her son Alex in 2015, for whom she had fought for the right to treat with cannabis products.

The following year she presented a 15,000-signature petition to Parliament, urging the Government to make medicinal cannabis more available.

In October last year, Kiwibank gave Renton a "Local Hero Medal", but the bank has just written to Renton to tell her that her bank account will be closed on September 14.

In a letter, posted by Renton on Facebook, Kiwibank refers to its general terms and conditions, which states that accounts can be closed if "we reasonably believe that you have acted, or are acting, unlawfully".

Renton said in her Facebook post that she received the letter today.

"Kiwibank awarded me as "Local Hero' in 2020 for supporting the sick and vulnerable in our community with cannabis medicines - yet they have sent a 14-day notice to close all my bank accounts due to the nature of my supporting the sick :( !!!

"Bullying at bank level, government level - what sort of society are we accepting?

"Please share so others are aware of their NZ owned bank and its policies... disappointing Kiwibank."

Rose Renton's Facebook post. Photo / Screenshot

In a comment in the post, Renton said the account was being closed "because patients pay to receive my Nz grown cbd oil that is organic, measured in mg and affordable! Yes they are closing access so patients can no longer deposit their $."

Asked about Renton's comments, Kiwibank external communications manager Kara Tait said: "Due to privacy, we don't comment on individual customers."

In February last year, Renton was discharged without conviction on charges of cultivating 58 marijuana plants, after a judge ruled a conviction could stop her becoming a supplier of medicinal cannabis.

Green MP Chloe Swarbrick, who has been a staunch advocate of making medicinal cannabis more affordable and available, said the illegality of cannabis had put the bank in a difficult position.

"Rose Renton was recognised as a local hero in the Kiwibank awards because of her efforts to ensure people in pain and suffering get access to medicinal cannabis.

"And the bank is trying to follow its rules, and right now cannabis - though incredibly widely used in this country - is illegal."

Swarbrick said the legal medicinal cannabis regime also put Renton in a difficult spot because selling CBD oil isn't illegal, but growing the plant to extract the oil is illegal.

"'Green fairies' are in worse than a grey area. They're left in the black market due to the current difficulties with the medicinal cannabis market.

"It's really gutting this has happened to Rose, but it also highlights how unjust the current system is.

"This is the very ugly side of the movement for change. That's why we need this 'yes' vote in the referendum [on recreational cannabis use]."

The Government passed legislation in 2018 to make medicinal cannabis more available and affordable, though products have to meet certain health and safety standards before they can hit the market after regulations were put in place at the end of last year.

The referendum on October 17 is about the personal use of cannabis, but proponents have argued that a "yes" vote would also see cannabis used more widely for medicinal purposes.