The warning follows two incidents on Thursday in which members of the public were contacted by a man claiming to be Detective Owen Carter from a cybercrime team in Ipswich. He told the individuals that someone had been arrested, and their details were found on the suspect's devices. This comes after fraudsters were reported to be using fake letters to carry out a sophisticated scam in Sudbury. The letters frequently reference an investigation by the National Crime Agency (NCA) and request that the customer send back their bank cards, with the promise that further contact will be made. Suffolk Against Fraud said: "Criminals rely on creating a sense of urgency, fear and authority to gain a victim’s trust."