The tests were ordered by authorities last month in response to growing concern about the product.
On Saturday, ambulance officers called for urgent police backup in Dunedin when they were confronted by two incoherent, aggressive men high on K2.
"I am concerned with reports about this substance, and I am keenly awaiting ESR test results on K2 samples that have been obtained by the police, and are being conducted on behalf of the police by the Ministry of Health," Mr Dunne said in a statement.
It could be a few weeks before he could confirm whether K2 would be added to the 28 banned substances and more than 50 banned products.
"I look forward to having the permanent psychoactive regime in place by the middle of next year, so we will have none of this kind of process.
"The manufacturers will have prove [under the new law] their product [is] safe before it could be sold, and we will not be dealing with this kind of very undesirable situation," Mr Dunne said.
