A man is in critical condition after a "serious incident" in a Porirua suburb overnight, police say.

Emergency services were called to Kotuku St, Elsdon, about 2am after a "man was located injured at the address". A scene guard remains at the property.

Detective Senior Sergeant Peter Middlemiss said inquiries into the incident are ongoing.

He said: "He was transported to hospital, where he remains today in critical condition.

"Police are now working to establish the circumstances of what has occurred, and a number of people will be assisting with our inquiries today.

"We would like to reassure the public this is believed to be an isolated incident involving people known to each other, and there is not believed to be any wider risk."