Police have seized £1 million of the date rape drug, GHB in a raid in Stanley, County Durham.
The drug, which is colourless and odourless when dissolved in water has in the past been linked to drinks being spiked by sexual predators.
GHB, also known as liquid ecstasy has become popular within the gay scene.
Detective Sergeant John Foreman said: “We are very pleased with the seizure, but it shocked us and is very unusual.
“It gives us cause for concern because it makes us wonder how widespread the use of this substance is.
“This raid has considerably reduced the risk of GHB being administered for illegal purposes.”
He added: “It is an extremely dangerous drug. Somebody can take it one time, but it can kill them the next.
“In date-rape cases, the intended purpose is to stupefy the victim so they have no recollection of the night before.”
Officers found the powder in an allotment in fist sized blocks. It was made a class C drug in 2003, following the death of users.