Update 3:50pm: The road is now open.

Central Otago Police are at the scene of a serious crash that has blocked Luggate-Cromwell Road (SH6) at Mount Pisa.

The crash involved a motorcycle and happened shortly after 10.30am this morning (Wednesday December 21).

The rider died at the scene.

The highway has been closed while the Serious Crash Unit investigates, the police said in a statement.

No other vehicles were involved.

The motorcyclist had come to the attention of police earlier in the morning due to the manner they were riding, police said. 

Enquiries were underway to locate it when the report of the crash was made.

Diversions are in place, via State Highways 8A and 8B.