"But the materials and equipment found in the room would suggest manufacturing occurred there."
The P lab went undetected by hotel staff because a "do not disturb" sign was placed on the door, Mr Litherland said.
Surapong Boonperm, 34, and Thi Thanh Nguyen, 29, have since appeared in court charged with manufacturing methamphetamine, among other offences.
The couple also stayed in several other rooms in the weeks before the police raid, which Mr Litherland said Environmental Science and Research staff tested as a precaution.
The risks of cooking methamphetamine include fire, explosions, chemical burns, contamination and poisoning, and the process also produces a toxic waste.
The Quadrant Hotel must now pass an Auckland Council inspection before the potentially contaminated room is declared safe.
When a lab is discovered, police notify council staff who serve a notice on the property owner requiring the building be tested for contamination and remediated if needed.
"We also serve a building notice to prevent [it] being occupied while the testing and decontamination is being carried out," said an Auckland Council spokeswoman. "At this stage only one room at the Quadrant requires decontamination."
Quadrant Hotel General Manager Edward Judd declined to comment yesterday.
Boonperm and Nguyen were on the run for five months before their arrests, wanted by police in connection with a P lab explosion which destroyed several West Auckland businesses in March. About 40 firefighters took two hours to control the fire in a flat above the industrial site in Waikaukau Rd, Glen Eden.
Mr Litherland, of Waitakere CIB, said Boonperm and Nguyen were charged with P manufacturing offences after equipment was found when the site went up in flames.
Nguyen, also known as Krystal or Sylvia, has also been charged over manufacturing items discovered in a unit at a St Lukes Storage King in July.
