The theft is thought to be the tip of the iceberg in terms of property stolen from the the red zone.
The large area of central Christchurch was closed off to the public because of the extensive damage to buildings, and need for demolitions and repairs, from the February 2011 earthquake.
Police have also dealt with other contractors who allegedly stole from the red zone, including plasterer Ross Larkin who is currently before the courts accused of stealing $1700 worth of property.
Jackson pleaded guilty to three theft charges in the Christchurch District Court yesterday and was refused bail and put into custody.
Police say Jackson took property from stores, including prominent retailers Ballantynes and Columbus and Ware Menswear, while working in the red zone between May 1 last year and January 31.
Police say more than $30,000 worth of goods were stolen by Jackson, and more than $18,000 worth of footwear from Ballantynes has not yet been recovered.
Jackson's lawyer David Bunce told the court that the values quoted by police might be disputed.
One bag of goods Jackson sent by courier from Christchurch to Tauranga weighed 66kg, while another five weighed 191.5kg, police said.
His advertisement in the Bay of Plenty Times for his garage sale in Mt Maunganui in January read: "Monster garage sale - clothes, books, shoes, jackets, all new jewellery and cosmetics".
Judge Brian Callaghan said any sentence other than imprisonment for Jackson was "unlikely" in his assessment.
Mr Bunce said Jackson had shared custody of his children and wanted to make arrangements for their care before going behind bars.
Jackson will be sentenced on May 16.
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* $30,000 worth of high-end goods was stolen from the red zone by a contractor.
* He took clothing, shoes, jewellery and cosmetics and sent it in bags by courier back to the Bay of Plenty to sell at the garage sale he advertised in a local newspaper.
* $18,000 worth of footwear from Ballantynes has not yet been recovered.
* He pleaded guilty to three theft charges.