Three people were arrested following seizures from two separate trucks at the channel port, according to a press release from the National Crime Agency (NCA).
Officers found 140 kilograms (309 pounds) of cocaine in a truck carrying a shipment of paper and card from the Netherlands, and 50 kilograms (110 pounds) in a second truck carrying toy building blocks. The two seizures on Monday are not thought to be connected, according to the NCA.
Gerrit Van Eckeveld, 62, from Nieuwegein in the Netherlands, was arrested by Border Force officers in relation to the larger haul. The cocaine was found in a void in the floor of the truck, police said.
He was later charged with importing cocaine and appeared at Medway Magistrates' Court Wednesday. Van Eckeveld was remanded in custody and will appear at Canterbury Crown Court on May 20.
The 50 kilogram shipment was found in two holdalls in the side lockers of a truck, and two Czech nationals were arrested on suspicion of importing cocaine. The pair were later released under investigation.
"These seizures demonstrate that the organised criminal networks involved in international drug trafficking continue to pose a threat to the UK, even with the restrictions brought about by the coronavirus pandemic," said NCA Dover branch commander Martin Grace in a statement.
Border Force regional director Dave Smith said in a statement: "This was a very successful day's work for our officers who, between the two seizures, have taken a very substantial amount of drugs taken out of circulation."
The southern English town of Dover is one of the main crossings into mainland Europe. It is linked to France by ferries to the ports of Calais and Dunkirk as well as the Channel Tunnel rail link under the English Channel.
In September, UK authorities seized almost 1.3 tons of heroin with a street value of £120 million ($148 million) from a container ship at another port, Felixstowe, in the nation's largest ever bust involving the drug.