A child has been approached by a stranger at a BMX park, sparking a major police hunt for a grey ute as investigators make an urgent appeal for information.

The 12-year-old was at Guthrie Park in Havelock North about 3.10pm on Friday when the stranger made an approach, Detective Inspector James Keene said.

Police are hunting for a vehicle believed to have been driven by the suspect. It is described as a grey Nissan Navara ute with roof racks, but without a canopy. The number plate remains unknown.

“Police know incidents such as this can cause concern in our community, however we would urge people to be alert, not alarmed, and take care to note your surroundings if you are out alone in a public place,” Keene said.

Detectives need to hear immediately from anyone who was in the Guthrie Park area, the carpark, or the BMX park between 2pm and 3.30pm on Friday.