LYNN – Police arrested several city men on warrants early Thursday morning in what a prosecutor for three of the men described as a “sweep” related to an FBI drug investigation.Anthony Purvis, 24, of 39 Congress St. #6, was arrested on a temporary warrant and charged with distribution of Class B crack cocaine, two counts.Elijah Johnson, 26, of 100 Light St. #3, was arrested and charged on a temporary warrant with distribution of Class B drugs, two counts.Mitchell Purter, 34, of 215 Fayette St. #2, was arrested on a temporary warrant and charged with distribution of Class B drugs, subsequent offense; at 6 a.m. Thursday.Each defendant was arraigned individually in Lynn District Court Thursday and a not guilty plea was entered on each defendant’s behalf.Assistant District Attorney Aimee Conway told the court that each defendant was charged in connection with a recently concluded FBI undercover investigation into drug dealing, specifically crack cocaine dealing, in Lynn.Conway said each case involved a confidential informant for the FBI arranging to buy and then purchasing crack cocaine from each defendant.In each case, the defendants were alleged to have sold first 7 grams, and then 14 grams, of crack cocaine to the confidential informant at various dates in 2011. In most of the cases, Conway told the court the defendant was captured in video and/or on audio recordings.Conway requested $25,000 cash bail for each defendant, citing the large amount of cocaine and previous criminal records for each defendant.Like Conway, the defendant’s respective attorneys found similarities among the cases.”It seems like this mountain of evidence here, but it all hinges on this confidential informant; this confidential informant who states certain things to FBI, has some things that are recorded, some things that are on video,” Attorney Todd Murphy, representing Johnson, said. “The likelihood of him being a credible witness is extremely low if he has associations with people whom he thinks are drug dealers, allegedly.”Murphy’s colleagues echoed his argument.Attorneys also questioned why police had waited more than two years to file charges and why the FBI sent a case to a district court.”This was an FBI investigation. It was probably presented to the Attorney General’s Office and they decided not to prosecute. Why?” Attorney Alicia Andrews, representing Purter, asked. “This is a bad case for the government.”Judges at the arraignments asked Conway to explain the delay in prosecution.”It is my understanding there was a warrant sweep today, from what was an ongoing investigation for FBI,” Conway told Judge Stacey Fortes at Purter’s arraignment. “In order to not compromise the ongoing investigation, they were waiting for the investigation to end before filing charges.”Fortes ordered Purvis and Purter each held on $10,000 cash bail.Judge James Wexler ordered Johnson held on $1,000 cash bail.Three other city men were arrested on Federal warrants and booked at the same time as the three men who appeared in Lynn District Court Thursday, according to the Lynn Police log.The U.S. Attorney’s Office, to whom Lynn Police directed inquiries about the incident, could not be reached Thursday.