The scheme enables branch staff to alert local police to suspected scams. The police then intervene and investigate.

In total, £174m of fraud has been prevented since the scheme was introduced in 2016, according to UK Finance.

The latest figures reveal that branch staff invoked the Banking Protocol 4,782 times between January and June 2021, saving potential victims an average of £6,672 each.

The scheme led to the arrest of over 90 suspected criminals, bringing the total number of arrests to 934 since the protocol began.

It is often used to prevent impersonation scams, in which criminals imitate police or bank staff and convince people to visit their bank and withdraw or transfer large sums of money.

It is also used to prevent romance fraud, in which fraudsters use fake online dating profiles to trick victims into transferring money, and to catch rogue traders who demand cash for unnecessary work on properties.

Katy Worobec, managing director of economic crime at UK Finance, said: “Criminals have continued to capitalise on the pandemic to commit fraud, callously targeting victims through impersonation, romance, courier and rogue trader scams. Branch staff and the police are working on the frontline to protect people from fraud and these figures highlight the importance of their work in stopping these cruel scams and bringing the criminals to justice.”

The scheme has been expanded to cover fraud carried out through telephone and online banking. So far, 36 out of 45 police forces across the UK are signed up to the enhanced scheme.

Staff working in call centres and in online banking teams notify the police when attempted bank transfers are being made which they believe may be the result of a scam.