The near two ton haul of cocaine, cannabis and Ecstasy is one of the largest seizures ever made by West Midlands Police.
It was being unloaded at a unit on the Maybrook industrial estate in Brownhills when a 30-string police squad struck at the culmination of a top secret under cover operation.
They pounced at around 5pm on Wednesday but details were only released today after a full assessment of the haul by forensic investigators, drugs experts and senior detectives.
The drugs were wrapped in protective foam chips and packed in layers in six large cardboard boxes measuring up to five by four feet.
They were stored on five freight pallets and wrapped in thick plastic bags taped closed with the cannabis vacuum-packed to stifle its tell-tale smell.
The haul was so large that officers needed a forklift truck to load it onto a police flat-bed lorry.
Two men aged 50 and 53 from Brownhills were arrested on suspicion of supplying a controlled drug along with a 51-year-old man from Norton in Stoke-on-Trent. All three who were arrested at the unit have been released on conditional police bail pending further inquiries.
Police show the massive haul of drugs found
Detective Sergeant Carl Russell, from Force CID, said: "This is the largest seizure of drugs I have secured in my 24 year career with West Midlands Police. It is also one of the largest in the force's 39 year history.
"You cannot under estimate the impact this will have on drug dealing in the region and the UK as a whole.
"The drugs had almost certainly been packed to order ready for shipping within Britain but possibly even further afield.
"Our operation will have a national affect and we are working closely with a range of law enforcement agencies to identify those involved in this crime at whatever level."
The haul is now being kept at a secret address under round-the-clock guard as experts chemically analyse the substances. Its value has been estimated at between £10 million and £30 million depending on its purity.
It included 120 1lb bags of cannabis, five 1kg bricks of cocaine and 50 1kg bags of MDMA which is also known as Ecstasy.
DS Russell commented: "Some people may believe that so-called recreational drugs such as these do not harm anyone but the reality is very different.
"Dealers are unscrupulous individuals. The drugs are incredibly harmful and can be cut with potentially deadly chemicals.
"The labs where they are made are highly dangerous environments which put neighbours at risk and those behind drug crime are almost always involved in gun crime, people trafficking and exploitation.
"West Midlands Police has a long track record of bringing serious and organised crime groups to justice.
"As well as securing convictions we will also look to seize any assets such as cars, jewellery and even houses bought through the proceeds of their crimes."
A large team of detectives continue to hunt those responsible but will not compromise the ongoing investigation by elaborating on the length of time the police operation has been running.
To shop a drug dealer call people should police on 101 or the independent crime-fighting charity Crimestoppers anonymously on 0800 555 111