Cocaine with an estimated street value of £13 million was been seized by British police, the force said today.
Six men were arrested after the haul was discovered when two cars were stopped and searched at a UK port yesterday morning.
Cumbria police said it is one of the biggest mainland seizures ever made in the UK.
Detective Chief Inspector Jeff Ashton, of Cumbria CID, said the port where the seizure was made cannot yet be identified for "operational reasons". He did say it was outside the Cumbria area and added that his force is now working with other police forces as a series of raids take place in Lancashire, Nottinghamshire, Lincolnshire and others.
He said: "It was discovered when two vehicles were stopped and searched as they entered the UK from mainland Europe yesterday morning.
"At this stage I don't want to disclose further details of how or where the seizure took place.
"This is because six males have been arrested and they are in custody awaiting interview.
"There are also on-going operations with about five other forces to trace others suspected of being involved.
"A number of private and business addresses across the UK are being raided."
He added: "I am absolutely delighted with the success of this operation and the fact that we have prevented such a large quantity of cocaine from reaching the streets of Britain."
The two vehicles were targeted on their entry into the UK following a long-running Cumbria police investigation alongside Lancashire Police and HM Customs.
PA