The officers recovered cocaine, heroin, amphetamines and cannabis with a total street value of £620,000.
The raid yesterday was part of Strathclyde Police's Operation Myriad and was described as being intelligence-led.
No arrests have been made yet after the operation at Larkfield Industrial Estate, Greenock.
A police spokeswoman said today: "Inquiries are ongoing."
Operation Myriad – a six-month police blitz on organised crime, gangs and anti-social behaviour – is now under way in K Division, which takes in Renfrewshire and Inverclyde.
It was launched by Strathclyde Police last year and every division across the force's area is taking part.
Chief Superintendent Alan Speirs, divisional commander of Renfrewshire and Inverclyde, said: "This was an intelligence led operation as part of our recently launched initiative, Operation Myriad, which aims to target all aspects of criminality, including drugs and drug dealing in our communities."