Hundreds of live redback spiders hidden in a vehicle imported from Australia passed undetected through quarantine checks to make it to a Penrose auto yard.

The car passed by Ministry of Agriculture and Forestry ports staff based on Auckland's waterfront had nests and "hundreds" of live redbacks, said the vehicle service centre manager who found them, Francis Cordes-Paki.

"This is the worst one we've seen but it's happened before," he said.

"MAF is putting its hand out for an inspection fee, but their inspections are a waste of time."

He was putting the late model Toyota Camry through its compliance certificate at Auto Belts and Mechanical Service Centre after it arrived from Sydney, when he discovered the creatures under the wheel arches.

He has found white-tailed and redback spiders in imported vehicles over the past two years "and I hate spiders".

He telephoned MAF at 3pm on Wednesday, but contractors did not arrive to fumigate the car until 10am yesterday. "I don't think that's quick enough," he said.

He says all cars imported from Australia should be be fumigated.

MAF Quarantine Services site manager Mike Fenton said the spiders were not found until parts in the wheel arch were removed.

"Given the location of the spiders and our current inspection procedures, I would not expect to have detected them," he said.

He was satisfied staff did a thorough check. On the delay in fumigating he said the contractor failed to do it immediately.

"Incursion investigators" would now monitor the site.

MAF was launching a pilot study with a micro-camera to check for insects that could not be spotted during a normal inspection.

A redback spider was found by a Reporoa farmer this month under a water trough. Populations of the spiders are suspected of having established themselves in the South Island.

* After being given the job of lead biosecurity agency last year, MAF was given an extra $45.6 million and underwent major restructuring.

Deadly redbacks

Each egg sac contains about 250 eggs.

Only females bite.

Redbacks caused 13 deaths in Australia before antivenin developed in 1956.

Symptoms: pain, sweating, nausea, vomiting.

Antivenin is held in 12 NZ hospitals.