Police are investigating after a man was found with serious injuries on a road near Taupo.

The man was at 4.45am this morning on Arataki Rd, Whakamaru - a small township north of Lake Taupo.

Police said they were working to understand how the man came to be injured.

The road was closed while officers worked at the scene, and motorists were told to expect delays or take an alternative route.

Anyone with information that could assist police was urged to contact call 105 referencing event number P054327032.