Six people have been arrested across Merseyside and Lancashire on suspicion of drug dealing.
Police raided addresses in Fazakerley, Norris Green and Lancashire following a year-long undercover investigation into the supply of class A and B drugs.
Five men, aged between 32 and 71, and a woman, 34, are being questioned over conspiracy to supply drugs.
A property in Runcorn, Cheshire, was also raided and a cannabis farm with more than 200 plants was uncovered.
All those arrested have been taken to police stations on Merseyside where they will be questioned by detectives.
Merseyside Police said that over the past year, drugs with an estimated street value of more than £1m had been uncovered as part of the operation and more than 20 people had been arrested.
A number of people have already been charged with drugs offences and have appeared before the courts.