An early morning Canterbury blaze seems to have narrowly missed a heritage site

Four fire trucks and a tanker responded to the fire on the grounds of Queen Mary Hospital in Hanmer Springs just before 4am.

A fire investigator will head to the scene of the suspicious blaze today.

Hurunui Mayor Marie Black says the historic site was used for soldier recovery after World War One.

However she understands the blaze was on the lower part of the site, away from the grounds' category 1 heritage buildings.