He has pleaded not guilty and the matter returns to court next week

Katelyn, 4, has suffered thousands of seizures from Dravet syndrome

His lawyers will defend the charges on basis of 'medical necessity'

The father of a little girl who has suffered thousands of seizures could face jail time after being charged with possessing and cultivating cannabis.

Micheal Lambert - whose rich list parents last year donated a record $33 million to medical cannabis research - was arrested by police last year.

He has pleaded not guilty and his lawyer said they will defend the charges on the basis he treated his daughter Katelyn, 4, with cannabis out of medical necessity.

Michael Lambert (right) was charged with possessing and cultivating cannabis. He is pictured with his daughter, Katelyn, wife Nui and grandmother Joy

Katelyn Lambert suffers from Dravet Syndrome, prosecutors have been told, and his lawyers will argue was treated with medical cannabis to minimise her seizures.

One of the charges relates to cannabis oil, said his defence lawyer Manny Conditsis.

The NSW Central Coast father's matter is set to return to Gosford Local Court next week after two months.

If found guilty, he could face a maximum sentence of two years imprisonment for each count.

His parents - semi-retired banker Barry Lambert and mother Joy - made history last year when they donated the multi-million dollar sum to Sydney University.

Semi-retired financier Barry Lambert and wife Joy (left, right) donated $33.7 million to Sydney University for medical cannabis research

The pair have an estimated fortune of about $350 million. Barry is a former Commonwealth Bank executive and is the chairman of Count Financial.

After the record-breaking medical research donation was announced this year, Barry said medical cannabis appeared to 'work miracles' for Katelyn.

He said they wanted to not just help her, but others like her.

'It's very hurtful when they have a seizure. No one wants to see a child sick when they're young,' he said.