Police are investigating an overnight house fire in Kaiapoi, which left one person with moderate injuries.

Emergency services were called to the blaze on Candy Crescent around 2.15am.

A police spokesperson  told chrislynchmedia.com the fire is being treated as unexplained and enquiries are underway.

A scene guard remained in place overnight, and a full scene examination is scheduled for today.

St John Ambulance confirmed it was notified of the incident and responded with an ambulance.

One patient in moderate condition was transported to Christchurch Hospital, a spokesperson said.