Northland police ask for public's help after body found on State Highway 1

State Highway 1 in the Brynderwyn Hills. Photo / Michael Cunningham

A couple who stopped to fill a water bottle were reportedly the ones to stumble upon a man's body in a waterfall along State Highway 1.

The grisly discovery was made shortly before 9am on Saturday when the couple, apparently travelling from Auckland, pulled over on the south side of the Brynderwyn Hills to make a freshwater top-up.

It is then that they allegedly found the man face down and unresponsive in the waterfall, which people traditionally throw money into for good luck and a safe journey.

The Advocate put this version of events to police, who replied saying they were not releasing any further information at that time.

What is sure is that the alarm was raised at 8.50am when a call was made to emergency services.

A lone police officer was then seen looking into the waterfall by a motorist passing through the narrow two-lane 80km/h stretch of highway, which has no footpaths.

At around 10.35am - nearly two hours after the discovery was made - police closed the southbound lane closest to the cliff that the small waterfall cascades down.

They respectfully covered the man's body so he was out of sight from vehicles headed north.

Waka Kotahi NZ Transport Agency announced via its Northland Facebook group that the road would most likely be closed for 30 minutes while the "incident" was responded to.

However, at 11.35am the agency announced a serious crash had occurred and the southbound lane would stay closed while the Serious Crash Unit investigated.

The unit carried out a scene examination between Waipū Gorge Rd and the turnoff to SH12, police said.

Thirty minutes later the "serious nature" of the crash meant the road closed completely and traffic was redirected via Waipū Gorge Rd.

The winding strip of state highway eventually opened at 3.10pm, close to five hours after it was first closed.

A community member travelled to where the waterfall is located and performed a karakia for the deceased man.

Yesterday, police released a statement that said indications suggested the man was likely struck by a vehicle.

A woman shared online how her friend had noticed a man at the waterfall in the dark on Friday night when the pair had driven past.

No details about the man - his age, name, or where he was from - had been released at edition time.

Detective Sergeant Dave Wilkinson called on anyone who may have witnessed "an incident" on the stretch of road to come forward.

"We are particularly interested in speaking with anyone who was in the area of Brynderwyn Summit and Artillery Road, between 7pm and 10pm on Friday evening," he said.

"We are also interested in hearing from anyone who may have dashcam footage that may be of use," he said.

Anyone with information can contact police on 105 and quote event number P051784129.