Police in the Southern district are warning Subaru owners to park off the street and fit extra security after a run of thefts in Otago that has climbed sharply since the start of October.

Inspector Sam Ramsay of Otago Coastal Police said officers had logged almost 30 reports of stolen Subarus across the wider Dunedin area since August, with a clear jump last month. Most were taken from public streets in residential suburbs, and in many cases there was little or no evidence of a break-in.

Police believe thieves are exploiting known weaknesses in some models. Asked by RNZ which models those were, police declined to say, arguing that spelling out the vulnerability would only help offenders.

Ramsay said the thefts were frustrating and disruptive for the people whose cars were taken. Many of the vehicles had since been recovered, but police were worried about stolen cars being driven around the district in the meantime. He said several leads were being followed and police wanted to hear from anyone who had seen people acting suspiciously around parked cars.

Subaru's New Zealand distributor, Inchcape, told RNZ police had not contacted it about the thefts or about any flaw in the vehicles, and that it was not aware of any security weakness in cars sold new in New Zealand.

The warning has been issued in Otago, but it matters south of the Clutha too. Subarus are a popular choice on Southland roads, where all-wheel-drive is valued for gravel and winter driving, and Invercargill and Gore are policed by the same Southern district that covers Dunedin. Police have not reported a matching rise in Southland so far.

The advice police are giving Otago owners applies anywhere. They suggest parking in a locked garage or off the street where possible, fitting a steering-wheel lock, immobiliser, alarm or another visible deterrent, and locking the car every time, including in the driveway at home.

Police ask anyone who sees a theft happening, or someone trying car doors in the street, to call 111 immediately. Thefts or suspicious activity that have already happened can be reported by phoning 105 or online at 105.police.govt.nz.