Sergeant Simon Irving of Masterton police said the Audi had been abandoned and a man was spotted fleeing the scene.
He was running across paddocks near the site of Masterton's new effluent treatment ponds.
Constables Nick Bunny and Rob Hutton gave chase in what proved a marathon effort.
They scrambled over fences and across farm paddocks, at times having to avoid electric fences, keeping the fleeing man in sight.
Mr Irving said the chase at one stage meant the fugitive and his pursuers had to wade the Ruamahanga River.
After a chase of 50 minutes and having covered several kilometres of farmland, the two constables caught the runaway. He was identified as a Featherston man serving three months' home detention.
According to Mr Irving, the man had cut the home detention bracelet from his ankle before leaving the house he was designated to remain in and took the motor vehicle.
The man was escorted back to Masterton police station, where he was charged with unlawfully taking the Audi and with breaching the terms of his home detention order. He will appear in Masterton District Court today.
Mr Irving said the two policemen who had doggedly stayed on the runaway's tail after he had abandoned the car had done good work.