The failure of a switch is the likely cause of a diesel leak that forced the closure of the Queenstown Lakes District Council's main office building yesterday.
The leak, first noticed by staff arriving at the Gorge Rd building about 7.30am, came from a rooftop storage tank.
Diesel leaked through the ceiling to the main office level and then down to the library, saturating walls and carpets in some areas.
Staff were forced to move to other council offices in downtown Queenstown and Frankton.
Council communications and engagement manager Naell Crosby-Roe said staff were unlikely to return to the building until next week at the earliest, although it was possible the library could reopen later this week.
He did not know how much diesel had leaked into the building.
Visitors to the council offices and library were turned away by firefighters while they and contractors attended to the spill yesterday.
Council corporate services general manager Meaghan Miller told the Otago Daily Times it would be "business as usual'' for staff, as they were able to work remotely.
The phone system would continue to operate as usual.
