On November 21 an oil sheen was spotted on the sea surface, around 400 metres from the Umuroa, the floating vessel which collects oil from Tamarind's three Tui oil fields, 50km off the Taranaki coast.
The EPA said Tamarind estimated that around 100 litres of oil had been spilled based on the size of the sheen, with a survey detecting a gash in the outer layer of the flowline from one of the wells.
Jason Kardachi of administrators Borrelli Walsh said the company was "actively taking steps to address the situation and is working with the regulator to mitigate its concerns".
He added: "We hope that these can be resolved in the coming days and our intention remains to continue and maintain operations."
On Tuesday the owners of the Umuroa, BW Offshore said it "has started preparations for disconnection and demobilisation" of the vessel, a floating production storage and offloading (FPSO) facility which has gathered oil from the Tui oilfields since 2007.
BW Offshore's contract with Tamarind was terminated in September and the company says the unpaid bill could hit its earnings before interest, tax, depreciation and amortisation by US$23m (NZ$35.8m).
As operator of the Tui fields, Tamarind Taranaki is liable for the clean-up and decommissioning of the wells on the sea floor when production comes to an end.
While Tamarind Taranaki's Malaysian owners have provided the Crown of a guarantee for the clean-up costs, its mounting troubles have raised concerns that it will not be able to cover the bill.
The Ministry of Business, Innovation and Employment has said if the company cannot cover the costs of the clean-up itself, the costs would fall on the Government.