Christchurch Police discovered a P Lab last night when they visited a house on Hills Road on unrelated matters.
Detective Senior Sergeant David Long says that just before 5pm last night police officers discovered the lab in the house where a 26 year old woman and two children, a male a female - both under five years old, lived.
The scene was guarded overnight and will be processed over the next few days by local staff and staff from the National Clan lab team.
The 26 year old female has been arrested and charged with allowing the premises to be used and failing to provide the necessaries of life. She will appear in court this morning.
Police are seeking a male, whereabouts unknown, says DSS Long.
"We believe we know who he is and he is not a danger to the public. The lab is of no danger to those who live in the area near it."