Local police are urging elderly Londoners to avoid falling foul of ruthless fraudsters who use courier firms to help defraud victims of their life savings.

Throughout the MPS's Courier Fraud Awareness Day today (20 March), Safer Neighbourhoods Teams (SNTs) in every borough will carry out activities to highlight crime prevention measures against the scam, which has impacted every borough and claimed 2,229 victims - mostly elderly - in two years.

Since January 2011, police have arrested 130 courier fraudsters and charged 93, including two brothers who have been jailed for more than 10 years for taking almost a quarter of a million pounds from over 200 victims (see case study below).

The fraud works by the suspect telephoning the victim and claiming to be someone from an authority - usually the police, bank or Serious Fraud Office. They tell them that their bank account has been compromised and their card must be collected. The most convincing element of the ruse is that the suspect instructs the victim to hang up and call the police/bank/Serious Fraud Office on a genuine number to check that they are who they say they are. The victim dials the new number but the fraudster does not disconnect so, unknown to the victim, they are still speaking to the suspect or a co-conspirator.

The fraudster then convinces the victim to reveal their PIN, usually by typing it in on their keypad. The suspect is able to tell which keys have been pressed. They then instruct the victim to put their bank card in an envelope and send a - usually unwitting - courier or taxi driver to the victim's house to collect it. The card is delivered to another suspect and is used, with the PIN, to empty the victim's bank account.

Police have identified that Organised Criminal Groups (OCGs) are behind the fraud but despite arresting many of these, courier fraud is continuing as new OCGs take over and convince victims that they are genuine.

The aim of Courier Fraud Awareness Day is to help stop Londoners becoming victims by showing them how the fraud works and teaching them the key crime prevention pointers. These are:

- Police and banks will never ask for your PIN or bank card

- Never give your PIN or bank card to anyone

- If you are contacted by someone who asks for these, hang up

- Use a different line to report it to police on 101 or allow at least five minutes for the line to automatically clear. Call 999 if the crime is in action.

SNTs and Operation Sterling, the MPS fraud prevention team leading the awareness day, will today:

- join 2,500 police cadets in letter-dropping fraud prevention flyers to homes across London

- give presentations to local elderly residents

- deliver courier fraud prevention flyers to banks, to be handed to customers

- set up courier fraud prevention stalls at transport hubs and key community areas

- make follow-up visits to victims and visit potential victims

- attend the Dementia Action Alliance quarterly meeting, to share their message with its 230 member organisations

- revisit some of the 3,000 cab and courier firms they have already advised on spotting courier fraudsters

Police are also asking friends and family of the elderly to share the crime prevention advice with them.

The MPS lead on organised crime, Commander Steve Rodhouse, said: "Courier fraudsters put a huge amount of time and effort into being convincing because for them the pay-off is immense. This is a massive part of what makes them so successful.

"We want people to question even truly genuine sounding calls and, most importantly, remember police and banks will never ask for your PIN or bank card, so you should never give these away.

"We are also urging courier and cab firms to be alert to anyone who may be using them to carry out this fraud. If you are asked to collect a package that you believe could be a bank card, do not make the delivery but call police immediately. You could prevent someone from being a victim of this terrible crime, and also stop yourself from being implicated."