Operation Century was the code name for a sting operation by Essex Police for investigating the Rettendon murders of three violent drug dealers that happened at Rettendon, Essex, England, in December 1995. It was assisted by RUC Special Branch officers. The purpose of the operation was to bring pressure to bear on persons whom they suspected of having knowledge to disclose about the triple murder in order to incriminate the suspects in question and/or others.
The operation produced no arrests or evidence leading to a criminal prosecution. A prosecution that was eventually brought in connection with the Rettendon Triple Killings was wholly based on police operations subsequent to the abandonment and closure of Operation Century. The tactics deployed by Essex and Royal Ulster Constabulary Special Branch while Operation Century was under way increasingly led to police voicing serious threats against the suspects in question. The operation was also carefully timed to coincide with the 1996 Docklands bombing of Canary Wharf on the evening of 9 February, which marked the ending of the previous mainland Republican bombing campaign cease fire. Any persons involved as witnesses during the triple killings were all successfully entered into a relocation and witness protection programme. One of the targeted Essex suspects received a call from Belfast within minutes of the Canary Wharf explosion. The Rettendon Triple Murders had absolutely no Irish connection in themselves or with the bombing. Irish affairs were introduced solely by police as part of the underlying leverage for their undercover operation.
Transcripts of these phone calls became available (see later and "sources" footnote) and police eventually had to acknowledge that they were made by Belfast based Special Branch officers. These calls were repeatedly made to the Essex suspects from Ireland by RUC Special Branch posing as Republican drug runners ("Irish Billy" and "Irish John") making it clear that they could rely upon organisational back up, and additionally claiming that they had funded the criminal activities of one of the Rettendon murder victims who they were still demanding repayment from. This ruse failed to result in the suspects agreeing to any meetings.