A woman from Watford had money stolen from her accounts after being conned into giving her bank cards to a fraudster.
The victim, who lives in Trinity Hall Close, gave her card details out after what Hertfordshire Constabulary described as an "elaborate con" between 4pm and 7pm on Wednesday, July 16.
Hertfordshire Constabulary has released an image of someone they would like to speak to in connection with the incident.
The offender is said to have impersonated a police officer, saying that someone had been arrested after trying to use her cards to buy some "expensive items".
Officers said that the man then asked the 58-year-old woman to provide the details for all of her cards and key in their pin numbers using the telephone keypad.
He is then said to have pretended to be someone from her bank, who arranged for a courier to visit her home to collect the cards as part of the investigation.
Police said that a password was agreed, so that the woman would know to trust the person calling at her address.
A man then arrived at her door and gave the password, before the woman handed over her credit and bank cards and money was then taken out of the account.
Police constable Carlie Thomas said: "Although the victim was not physically harmed by the offender or offenders, the caller was extremely persistent and persuasive.
"He kept her on the phone for several hours throughout the scam and applied an enormous amount of pressure on her, making her feel flustered and distressed. She was understandably left feeling extremely upset by what happened.
"I would like to speak to the man in the photo as he may have information that is useful to our investigation. If you believe you recognise him please get in touch with me as soon as possible."
Anyone with information about the incident is asked to PC Thomas on the non-emergency number 101. Alternatively call Crimestoppers anonymously on 0800 555 111.