The grandparents of a five-year-old with terminal brain cancer have called in a lawyer after doctors refused to consider medical cannabis to treat the child.

In August last year the child was given nine to 12 months to live after being diagnosed with an inoperable tumour on her spinal cord.

Her father also wants her to receive medical cannabis treatment, despite protests from the girl's mother.

Lawyer Rosie Purchas told Morning Report they had been encouraged by reading about the successful treatment of a child with the same condition in America.

She said doctors in New Zealand had refused to offer treatment with medical cannabis because they said there was no supporting evidence, which she said was denying the child's human rights.

Study of teenage twins finds little evidence that using marijuana lowers IQ.

Roughly half of Americans use marijuana at some point in their lives, and many start as teenagers. Although some studies suggest the drug could harm the maturing adolescent brain, the true risk is controversial. Now, in the first study of its kind, scientists have analyzed long-term marijuana use in teens, comparing IQ changes in twin siblings who either used or abstained from marijuana for 10 years. After taking environmental factors into account, the scientists found no measurable link between marijuana use and lower IQ.

Medical cannabis helped ease the suffering of a terminally ill teenager but did nothing to treat his epilepsy, a medical report says.

The 10-page review is being cited by campaigners for the legalisation of medicinal cannabis as further proof as to why there should be a referendum on the issue at the next election.

The report discusses the treatment of Alex Renton, 19, who suffered from "status epilepticus", a kind of prolonged seizure, and was the first person in New Zealand to receive medicinal cannabis in hospital.

His family campaigned to have medicinal cannabis used in his treatment after his seizure in April. His mother, Rose, secretly administered Elixinol, a cannabidiol (CBD) product from the United States called, to her son when no one was around.

Some of Northland's largest organisations are tightening up their drug testing policies for staff amid stricter workplace regulations amid news the region's rate of failed employee drug tests after workplace incidents is more than double the national average.

Glenn Dobson, group general manager of the New Zealand Drug Detection Agency (NZDDA), which operates a branch in Whangarei, said its most recent figures showed 13.4 per cent of post-incident tests in Northland returned an indication of drugs against the national average of 6.4 per cent.

The region's lead drug detection agency also revealed that during random testing in Northland in 2014, 8.6 per cent of employees returned an indication of drugs present, against a national average of 5.3 per cent.

The Māori Party say it's highly unlikely they would support the legalisation of cannabis given the dire effects the drug has had on Māori communities.

Ex-president of the Council Trade Union, Helen Kelly, who uses cannabis oil for medicinal purposes, is calling for a referendum to legalise the drug.  The New Zealand Drug Foundation says politicians need to "wake up" over the issue. 

The NZ Drug Foundation say politicians need to stop beating around the bush over the legalisation of cannabis.

Ross Bell says, "I think on this issue we need to grow up.  I think because it's cannabis it's a dirty word.  Politicians are really scared of that, they think if you do something on cannabis the floodgates are going to open and everyone is going to be smoking cannabis."

Referendum welcomed by Cannabis Party

A move towards holding a referendum about cannabis at the next election is welcomed by the Cannabis Party.

Former CTU president Helen Kelly launched the referendum campaign after she was forced to obtain cannabis oil illegally to treat her cancer.

However, Family First's Bob McCoskrie has claimed the move will be used a back-door to recreational use.

"Mr McCoskrie's blind fear is misguided as recreational use would be treated as a separate issue to medical cannabis in any referendum," party leader Julian Crawford said.

"Family First needs to clarify whether they support the democratic referendum process and whether they think sick and dying people should have access to medical cannabis."

Terminally ill former trade unions boss Helen Kelly wants a referendum on whether cannabis should be legalised, and says she is talking to MPs about making it happen.

Kelly, who has lung cancer, has been taking cannabis oil sourced from the black market to relieve her pain and believes it is "absolutely ludicrous" New Zealand's laws have forced her to do so.

"If we can have a referendum on the New Zealand flag, then we can have a referendum on this issue," she said on Saturday.

Every day, there is news from somewhere in the world of progress and developments in respect of legalising and regulating cannabis. This applies particularly to the American continent and Europe. However, there is a third continent that is heading in the same direction: Oceania, and in this article, we focus on New Zealand, one of 14 independent countries that make up that continent and where use of medicinal cannabis may become legal  as soon as 2016.

John Lord once walked into a federal government building with $2 million in cash in his backpack to pay his taxes for the cannabis he sells. 

Due to federal laws, he couldn't get a bank account to bank his drug profits. It's different now. His customers still have to pay cash, but he can now transfer money to the Internal Revenue Service come tax time.

Lord is the chief executive of Livwell - the largest marijuana dealer in Colorado, one of a few states that have legalised cannabis.

He sells in excess of $80 million worth of product annually. He won't talk profit margins.  

John Lord once walked into a federal government building with $2 million in cash in his backpack to pay his taxes for the cannabis he sells. 

Due to federal laws, he couldn't get a bank account to bank his drug profits. It's different now. His customers still have to pay cash, but he can now transfer money to the Internal Revenue Service come tax time.

Lord is the chief executive of Livwell - the largest marijuana dealer in Colorado, one of a few states that have legalised cannabis.

He sells in excess of $80 million worth of product annually. He won't talk profit margins.