A fire that has ripped through a well-known Christchurch heritage mansion overnight is being treated as suspicious.
Fire and Emergency New Zealand were called to Antonio Hall on Riccarton Rd after 3.30am and found it ablaze.
Antonio Hall is a Category 2 Historic Place and firefighters remain at the site today dampening down hot spots and the last of the flames.
Neighbours in the area were evacuated as 12 fire crews fought the blaze.
All traffic cordons on Riccarton and Wharenui Rds had been removed by 10.45am.
A police spokesperson said they are investigating along with fire investigators from Fire and Emergency New Zealand.
"The investigation is in its very early stages," they said.
Built around 1904 for a successful grocery merchant, the grand site was purchased by the Catholic Church in 1946 as a place to educate young men entering the priesthood.
The church added to the original building - including a chapel and accommodation.
It was later used as a private hostel for students attending nearby Canterbury University and was then sold to a family who gave it its current name.
The site was badly damaged in the 2011 earthquake and has fallen further into disrepair over the past decade despite efforts from the local community to restore it.
Fire and Emergency's Wayne Hamilton says it's disappointing to see another historic building go up in flames.
He says Antonio Hall has been the target of arsonists in the past.
Last year almost a third of the mansion was destroyed when a teenager set fire to a mattress inside one of the buildings.
Since then it has been a target for vandals and thieves.
Fire investigators will be at the site later today and will start working to find out the cause of the fire.