DETECTIVES are hunting a "despicable" crook who preyed on a pensioner.

Police said the bogus caller conned the 77-year-old woman into handing over £40 - before returning in a bid to get even more money.

He struck at her home in Devon Road, Blackburn, claiming to have done work on her guttering for which he needed payment.

The incident happened last Monday about 2pm, but details have only just been released. Police said a man knocked on the front door and said he had come to collect money for previously agreed guttering work.

The victim told the man she had no knowledge of any work.

A spokesman for Blackburn Police said: "The offender intimidated the aggrieved, gained entry to her house and then asked for £90. She gave him £40, which was the total in her purse. He asked for a cheque for the remainder, but the aggrieved did not have a cheque book to hand. He took her phone number and made off.

"The offender then returned and knocked on window for her to let him in but she refused. He phoned to say he would send a receipt in post for her in due course."

The spokesman added: "This is a despicable offence. We would like to hear from anyone who has had a similar visit. Anyone who receives suspicious visits should make sure they check identification."

The offender is described as stocky, aged 50-60, 5ft 4in, wearing a dark hat, suit jacket, brown woollen cardigan, dark blue shirt, dark blue work pants, brown work boots, grey white hair, missing lower teeth, local accent and quietly spoken.

If you can help, call 01254 51212 or Crimestoppers on 0800 555 111.