Two demolition companies working in Christchurch have been stripped of their accreditation, after employees were caught acting suspiciously inside the city's red zone.
Civil Defence says it is the first time that any companies have lost their accreditation, which demolition firms must have in order to work clearing debris from last month's earthquake.
National Controller Steve Brazier says police caught two people working in the red zone in what he described as suspicious circumstances on Friday, but could not be more specific.
He did not know what, if any, charges would be laid.
Demolition companies have faced accusations from business owners of theft from central city buildings.
Mr Brazier says while any such reports are regrettable and unacceptable, demolition workers are not the only ones with access to cordoned-off areas.