Two air conditioning units bound for Wellington Hospital to increase capacity for Covid-19 patients have been damaged in a suspicious fire over the weekend.
Police were advised shortly before midnight on Sunday of a truck-and-trailer fire in Ōtaki.
The truck was parked at a property on State Highway 1, a police spokesperson said.
"The fire is being treated as suspicious at this stage, police are back at the scene this morning, and continuing to make further inquiries."
Capital & Coast DHB chief financial officer Rosalie Percival said two units were affected by the incident and needed to be repaired.
The two affected units would have increased Wellington Regional Hospital's negative pressure capacity by about 16 beds.
Currently there are 22 negative pressure rooms across the hospital as well as several clinical spaces that can be used to ease pressure on these rooms, Percival said.
"The units were insured, and are expected to be in place at the hospital by the end of this week."
Negative pressure rooms use lower air pressure to prevent internal air from reaching other patient areas and common spaces in a hospital, allowing patients with infectious conditions to be isolated.