Two more men have been charged following the discovery of 140kg of cocaine hidden inside two lorries.
The drugs, with a street value of £15m, were found at Harwich Port in Essex as part of a long-running inquiry co-ordinated by Cumbria Police.
Phillip Grange, 54, of Park Valley in Nottingham and 32-year-old Simon Finlay from Park Lane, Preston, are charged with conspiracy to import cocaine.
They are due to appear before Kendal magistrates on Thursday.
Darren Morris, 32, Mark Neville, 41, both of Preston, and Peter Hannigan, 49, of Kendal, have already been remanded in custody on the same charge.
Mr Neville and Mr Hannigan are also charged in connection with the seizure of amphetamine, valued at £10,000, which was found in Preston.
Two other men, from Melton Mowbray in Leicestershire and Grantham, Lincolnshire, have been released without charge pending further inquiries.
The lorries where the drugs were found are believed to have come into the UK from Holland, according to police.