Thirty-five suspected drug dealers have been arrested across East Sussex during a series of police raids.
Sussex Police said the operation was targeted at disrupting the supply of crack cocaine and heroin in Hastings and Eastbourne.
In total 40 officers were involved in the six-month undercover operation codenamed Operation Colne.
The men and women, aged between 20 and 50, were being questioned by detectives in custody.
Ch Insp Mark Ling, of Sussex Police, said: "We've got difficult times ahead and we know we've got tough choices to make.
"But the supply of heroin and the impact that it has on our communities will remain a priority for us."