A woman was busted selling methamphetamine to an undercover police officer while she was breastfeeding her young baby as part of a nationwide drug sting.

The seven-month long undercover police operation targeting drug-dealing houses, which saw more than $11 million worth of property seized, has left police concerned about children living in drug-dealing houses.

The Bay of Plenty incident involving a mother breastfeeding her baby while engaged in a methamphetamine deal was just one of 40 children, aged between 3 weeks and 16 years, found in drug-dealing houses across the country.

Detective Inspector Craig Scott, from the National Crime Group, said this was completely unacceptable as the dangers and risks children faced from being exposed to drugs and the drug environment was enormous.


"Police are determined to shut down drug-dealing operations to prevent the significant social harm they cause the community, the users and their families," Mr Scott said.

Nationwide, 155 people were charged as a result of the operation, called 'Operation Province' which wrapped up last week.

Bay of Plenty police and eight other police districts were involved in identifying and dismantling drug supply chains operating from more than 100 addresses.

A police spokeswoman said 18 drug-dealing houses were searched by police in the Bay of Plenty during the operation, resulting in 27 people being charged with 74 offences.

"Notably in this region, more than $20,000 in cash has been seized by police, as well as 61 grams of methamphetamine, 1.9 kg of synthetic cannabis and 46 cannabis plants were also seized or destroyed," she said.

Bay of Plenty Detective Senior Sergeant Lindsay Pilbrow said the work carried out in the operation would have an impact on drugs and organised crime throughout the Bay of Plenty district.

"These operations are targeted at disrupting these groups, stopping their cash flow and preventing the harm they cause to our communities," he said.

Mr Pilbrow said children should not be subjected to the dangerous environment a drug-dealing home presents.

"Methamphetamine causes harm both because of the involvement of organised crime groups and because of the harm caused by its use and manufacture," Mr Pilbrow said.

During the operation officers around the country successfully infiltrated a number of organised criminal gang operations, resulting in the arrest of two separate gang chapter presidents.

Mr Scott praised the efforts of undercover officers and their support teams.

"This undercover work carries a high level of risk and considerable courage and determination is required to infiltrate these groups.

"Our belief is that drugs are one of the main drivers of other criminal offending so we're pleased we've been able to identify and disrupt this activity," Mr Scott said.

Part of the success of the operation was because people stood up against drugs and the harm they cause to their community and provided police with vital information.

The countrywide drug operation resulted in:

* About 900 grams of methamphetamine (with a wholesale value of about $750,000) seized

* 42kg of cannabis plant material (with a wholesale value of $376,000) seized

* 89 cannabis plants seized

* Seven firearms seized, one of which was bought by an undercover officer and one which was found loaded and easily accessible

* 46 addresses were selling methamphetamine, 70 addresses were selling cannabis, and seven addresses were selling synthetic cannabis

* 26 of the properties targeted were selling both cannabis and methamphetamine

* 791 charges have been laid against 155 offenders