It was common for police to stumble upon clandestine labs while executing search warrants on other matters but that was not the case last year, which suggested there could be fewer in operation, he said.
The only P lab found last year came to police attention in April when it blew up, badly injuring a man in the Oceanbeach Rd house.
Mr Pilbrow said there was one investigator in the Western Bay whose sole focus was educating chemical suppliers and getting them on board with voluntary measures to make it harder for people to get hold of ingredients to make methamphetamine, including Contac NT and toluene.
"I think there's been some really good prevention work done around the stuff, particularly around the availability of the precursor materials that these guys need," he said.
"We're getting [distributors] to ask for ID. In bulk purchases we're getting them to fill out an end-user document that explains what it will be used for. For any legitimate buyer that's no issue at all but when you get people that are buying it for these types of things, they are not so keen to fill out those forms or give contact details or vehicle details."
It was a "complex phenomenon" and factors including known P cooks serving jail time could have played a part in the drop, Mr Pilbrow said.
Meth Solutions director Miles Stratford said his company had tested 49 houses in the Bay of Plenty for methamphetamine last year.
Of those, 53 per cent were contaminated - the level of contamination in five of those suggesting the drug may have been manufactured in them.
"I have a personal view there might be a few less of the bigger ones but it's still there as an issue and a risk."
Studies suggested more than 20 per cent of long-term P users had a go at making the drug at some point, Mr Miles said.
"If there are people out there that are manufacturing for themselves and their mates they are still contaminating houses out there."
P Labs found by police
2012
Western Bay: 11
Total Bay of Plenty: 15
National total: 95
2013
Western Bay: 1
Total Bay of Plenty: 3
National total: 77
*The 2013 figures are provisional pending the results of further tests.