Police said they were alerted by a relative at 9.30am that the man was in an agitated state, and there were "serious concerns for his welfare". He could not be found at his work or home.
Police located the man's car shortly before 10am in Greenhithe, but the driver failed to stop and a brief pursuit followed after police turned on their lights and sirens.
According to police the chase lasted about a minute, and stopped due to concerns for public safety. Instead a police chopper followed the car.
About 25 minutes later the car pulled into the driveway of the Wairere Road house before driving out again. A police unit attempted to approach but the man drove off towards Horsman Road.
A short time later the car was seen speeding over the cliff, police said.
At the site a broken farm fence is all that can be seen of where the car left the gravel road.
Landowner Greg Jonkers said he received a phone call from police informing him of the crash after 11am.
"They just said there'd been a mishap at the place here. It's a bit of a tragedy," he said.
"My wife said she saw police cars chasing [a car] back more towards the city, so [they must have] found their way right up here."
He said the death was "devastating for the person involved and their family".
Mr Jonkers said the car had ended up on its side in the hay paddock of the sheep and beef farm.
A tow truck driver at the scene said a tractor would be needed to remove the car from the gully it had landed in before he would be able to get it onto his truck.
"It's quite involved," he said.
The circumstances surrounding the death will now be investigated by police and it has been referred to the Independent Police Conduct Authority.
The man's next of kin were being informed and his name would not be released until then, police said.
