Asked why police raided the dairy, the woman told the Herald: "No drugs, I'm housing people, okay?"
She refused to comment further.
The dairy is one of several shops in a busy block of shops on Main South Rd.
Its doors remain open.
A police spokeswoman confirmed that a search warrant was carried at out the dairy at 11am "as part of a follow-up" from last week's synthetic drugs crackdown.
No arrests were made today.
Police say they expect to release further information on the raid later this week.
Last week's raid hit a major supply chain for synthetic drugs entering the South Island and led to five arrests, police said.
Officers from the Canterbury Organised Crime Taskforce stormed 10 addresses across Christchurch over two days.
They seized "a significant amount" of psychoactive substances as well as the products used to manufacture the illegal drugs, Detective Senior Sergeant Jason Stewart said.
The raids have blocked hundreds of thousands of dollars' worth of synthetic drugs from the reaching the South Island black market, he said.
Five people are now facing charges in relation to the distribution network.
