Two people have been injured - one seriously - in a crash in the Tasman district. 

Emergency crews were called to State Highway 65 in Maruia after reports that a vehicle had rolled along the highway between Memorial Lane and the Shenandoah Highway. 

The incident happened just after 8.30am. 

Police said two people were injured. One person suffered serious injuries and the second received moderate injuries in the crash. 

The circumstances of the accident are not yet known and the Police Serious Crash Unit has been advised. 

Motorists in the area are being told to expect delays or delay travel times as a result. 

Diversions have been put in place. Police are telling drivers that these will likely be through Reefton. 

"We thank motorists in advance for the patience."