A witness said a police chase through Blenheim ended with the driver "screaming in agony" and bleeding after being shot by police.
Police confirmed they had shot a knife-wielding man in the arm after he failed to stop when pulled over by police.
The police chase ended by Montana Winery on State Highway 1, south of Blenheim, just before 4pm.
Acting Tasman district commander Inspector Virginia Welch said the man, who was wanted by police, failed to stop on SH1.
Spikes were deployed and the vehicle came to a stop at an intersection of Hardings Rd on SH1.
The man - who allegedly presented a knife - was shot in the arm.
Stuff reported a witness saw the man get out of his car after the chase, run over to an unattended police car and get inside.
An officer with a gun then confronted the man, who got out of the car and walked towards police before being shot, the witness told Stuff.
"You could see a lot of blood and you could hear him screaming in agony. He fell down on his stomach and then two police officers took him into custody," the witness reportedly said.
Police immediately issued first aid and the man was transported to Wairau Hospital, Welch said.
The alleged offender is under now police guard.
Cordons are in place and people are asked to avoid the area.
Police staff involved in the incident are receiving support.
"Our police staff come to work every day to ensure the safety of the public and no officer should ever be put in this position," Welch said.
St John ambulance also attended the incident. A St John spokesperson referred media to police.
New Zealand Transport Agency is warning motorists SH1 between Malthouse Rd and Cloudy Bay Rd has been closed due to a police incident.
Motorists are being urged to follow directions of emergency services and to delay their journey if possible.