Police are investigating several incidents in Tasman where vehicles have had their petrol tanks drilled and drained while parked in Department of Conservation (DOC) carparks.
In the last month there have been seven reports of petrol being drained from tanks in vehicles parked overnight in the Siberia Flat carpark near the Wanagapeka River (May 5-6), at the Flora Carpark in the Kahurangi National Park (5 May) and at the Hackett Hut carpark in the Aniseed Valley (27 April - 2 May).
Nelson Bays area prevention manager Senior Sergeant Adam Ramsay said in most cases a hole had been drilled through the petrol tank and the fuel syphoned.
"Most vehicle owners have only noticed the theft after leaving the carpark and realising their fuel tank is empty or significantly drained.
"Inspection of the vehicles shows that in some cases the holes have been hurriedly patched with putty or chewing gum by the offender after draining the tank."
Police are working with Department of Conservation and security contractors in an effort to identify the offender/s.
Ramsay said there may be more incidents that have not been reported as they have gone unnoticed due to the efforts to patch the holes.
Police wanted to hear from anyone who may have had their petrol stolen - or who had seen suspicious activity in those areas on the dates mentioned.