Christchurch, Feb 5 NZPA - A man who torched a Christchurch shopping mall causing damage estimated at $1.7 million alerted police to the blaze and gave his name and details, a court was told today.

Robert James Shingleton, 29, pleaded guilty in Christchurch District Court today to arson of the Westfield Shopping Mall in Riccarton.

The fire caused $235,000 damage to the mall and $1.5 million smoke and water damage to the stock inside Farmers Department Store.

Shingleton also admitted starting a series of minor fires following the Westfield blaze.

Judge Tony Couch remanded him on bail for sentencing on April 30. He asked for a probation report to cover his suitability for home detention.

Defence counsel Pat Butler admitted Shingleton's ability to pay reparation was "zilch" and no reparation report was ordered.

Shingleton had been remanded on bail to today, to live at his parents' home in Westport, while a psychological report was completed.

Judge Couch told him: "Normally in these circumstances I would remand you in custody, but I am not doing that because of what's in the psychological report and the support you have from your parents.

"If there are any problems on bail you can expect to be held in custody, and that would be most unfortunate."

The court was told that Shingleton walked to Riccarton after a night's drinking last July. He set fire to some rubbish wheelie bins and then went into a service lane beside the mall where two skips were full of cardboard.

He tried three times to light them and run away to watch, but the fires went out. The fourth caught hold and quickly grew in intensity as it spread up the Farmers store's rear wall.

"Plumes of thick black smoke filled the air and entered the Farmers store," police said. Sprinklers were activated by the smoke.

Shingleton's actions were caught on the surveillance cameras as he walked away.

He waved to a police officer to point out the fire and the officer took down his personal details.

The officer later noticed that Shingleton's clothing was the same as the person in the surveillance images.