A 21-year-old man was sentenced to six months in prison at St Albans Crown Court on Wednesday, after he scammed a retired couple from Radlett.

Conrad Mukama of Fontwell Close in Northholt pleaded guilty to conspiracy to commit fraud between March and May 2013.

On the evening of May 26, 2013, the retired couple were contacted by someone claiming to be a police officer investigating fraudulent use of their bank cards.

They were told that arrests had been made and that their bank cards were needed as part of the investigation. A courier came and collected the couple's bank card.

The following day they found that hundreds of pounds had been withdrawn from their account and realised the call was a scam.

Later that week, the couple were contacted again by a fraudster, but being aware of the scam, they kept the caller on the line whilst they contacted the poilce.

As a result, officers were able to investigate the matter and this led to a warrent being executed at Mr Mukama's address in London.

Analytical work carried out on his phoneline revealed links to not only the offence in Radlett but two other offences in London.

Detective Constable Darren Machin, who led the investigation, said: "It has take some time to get this case to court due to the complex nature of our investigation and we are happy the court has taken the serious nature of this offence into consideration.

"This has been reflected in the sentence, which is significant considering this was Mukama's first offence.

"This was a despicable crime as Mukama preyed on the trusting nature of his victims and I hope this sends a clear message to anyone involved in phome scams."

Hertfordshire police have advised residents that the police would never ask for bank details and PIN numbers over the phone and nor would they ask anyone to send their bank cards or any other personal property to them via a courier, taxi or other means.

Further information on phone scams and how to avoid becoming a victim can be found at www.herts.police.uk/PhoneScams.