Emergency services are at the scene which is just west of Kopu, and motorists are advised to consider avoiding the area if possible.
A detour is in place via Canal Road East, State Highway 2 and Pipiroa Road then back onto SH25 for northbound traffic, and vice versa for traffic heading south.
For personalised information about driving conditions on their frequently used routes, motorists can sign up to On The Move at www.onthemove.govt.nz.
For real time information on highway conditions and incidents or to report issues on the network visit www.nzta.govt.nz call 0800 4 HIGHWAYS or follow @nztawaibop on twitter.