Police in Christchurch have seized thousands of capsules of the illegal drug BZP and arrested eight people during an operation.
Fifty police staff searched a Christchurch retail store, three lock-ups and several homes on Tuesday.
BZP is a class C drug that was made illegal in 2008.
Detective Sergeant Chris Roberts says the drugs were disguised as legal herbal products.
Some of those arrested have already appeared in the Christchurch District Court.