New Zealand Police have been undertaking mass riot training ahead of the signing of the Trans-Pacific Partnership in Auckland next month.
The trade agreement, that has sparked widespread controversy due to its closed-door negotiations, will be signed by international diplomats on February 4.
Dozens of large-scale protests have been held across the country as the five years of negotiations for the deal came to a close in the US last year.
The Herald understands that increased riot training - officially known as public order training - has been taking place ahead of the signing, as police prepare for more possible civil unrest.
Police Association vice-president Senior Sergeant Luke Shadbolt said that the TPP signing was the focus of annual public order training.
The Herald understands that the training goes over and above previous annual training, and involved more staff on a "mass" scale.
Police National Manager of Response and Operations, Chris Scahill, said police were responsible for all security aspects of the event.
He would not be drawn on any operational details for the event - including staff numbers.
"We can however say that we plan for every eventuality which can be anticipated, and the measures we take will be appropriate and thorough."
The police operation will be overseen by Police National Headquarters, and will involve staff from a number of police districts."Under the 12-nation TPP trade deal, New Zealand joins a club that accounts for 40 per cent of the world economy.
The TPP will eliminate tariffs on 93 per cent of New Zealand's exports to the United States, Japan, Canada, Mexico, and Peru.The Government estimates the agreement will be worth at least $2.7 billion a year by 2030 for New Zealand.