Officers discovered the 1.1 tonnes of the Class B drug following a search of a container that had arrived at the port from Ghana.
Border Force Assistant Director for London Gateway, Mark Kennedy, said:
The load had been manifested as sacks of corn husks and corn flour, but when officers started to unload the sacks they found a heap of cardboard boxes buried underneath. All the boxes, 42 in total, were stuffed with shrink-wrapped blocks of cannabis.
By making this seizure, worth an estimated 2.3m, Border Force officers have prevented a substantial quantity of illegal drugs from ending up on the streets of the UK.
The Border Force seizure was made on 12 September 2015 and the case was passed to the National Crime Agency who continue to investigate.
Border Force officers are at the front line in protecting the country and play a key role in detecting illegal immigration, disrupting serious and organised crime and helping to prevent the threat of terrorism. Border Force also protects UK revenue, contributing to the nations prosperity and growth.
They use an array of search techniques including sniffer dogs, carbon dioxide detectors, heartbeat monitors and scanners, as well as visual searches to find well-hidden stowaways, illegal drugs, firearms and tobacco which would otherwise end up causing harm to local people, businesses and communities.
Anyone with information about activity they suspect may be linked to smuggling can call our hotline on 0800 59 5000.