The discovery of a pipe-bomb at a house containing one of New Zealand's largest P-labs is slowing down the clean-up, police say.
The clandestine methamphetamine laboratory -- one of the five biggest such labs uncovered to date -- was raided by police on Thursday at Newcastle Rd inDinsdale, Hamilton.
The operation to decommission the lab was due to be completed today but had been delayed by the extremely high level of contamination at the house, and the discovery of explosives.
" If the potential risk of explosion from the volatile mix of chemicals found in the property wasn't enough for searchers to deal with, the discovery of a small amount of black powder explosive and a device that appears to be a pipe bomb has meant additional precautions have had to be made," said Detective Senior Sergeant Mike Whitehead.
Mr Whitehead said members of the 30-strong team of police, fire and ambulance staff had suffered sore throats and headaches due to exposure to the hazardous chemicals -- despite being in the open air.
The clean-up was a laborious process, he said.
"The address contains not only large quantities of chemicals used for the manufacture of meth but also large numbers of containers with waste from the chemical process which are dangerous on their own...this necessitates extreme care be taken by the police and ESR clan lab team."
Mr Whitehead said neighbours had been allowed back into their homes last night, and traffic access along Newcastle Rd would go back to normal tomorrow.
Police were still in discussions with Hamilton city council staff and the property's owner, about whether it would need to be demolished.
The sole occupant of the rented property, a 49-year-old Hamilton man appeared in the Hamilton District Court on Friday on six charges of possession of precursor materials for the manufacture of methamphetamine and one charge of manufacturing methamphetamine.
