The stolen materials, far from being fit to produce illegal drugs, are actually oils made from the anal glands of stoats.

If the thieves open up the bottles, which belong to conservation company Goodnature, they’ll be in for a nasty surprise.

Robbie van Dam, director of Goodnature, explained: “Stoat anal gland oil is extremely smelly stuff and it lingers on any fabric or surface.”

The potent oil was in the process of being moved off-site for storage.

Mr van Dam added: “We popped a gland in our lab a couple of years ago during research.

“We had fans running and windows open in the middle of a Wellington winter, and it still took weeks to go. Some staff chose to work from home for a couple of days.”