Courier fraudsters are having a tough time of it lately but it seems honest folk are increasingly wising up.

First a man was convicted of fraud after being foiled by world-renowned philosopher and Primrose Hill resident Jonathan Glover, and now a leading member of an influential conservation group has outwitted the scammers.

Frank Harding, vice chairman of the Heath and Hampstead Society, was fed one of the most elaborate tales yet.

He was told by a caller that someone posing as his grandson “Jasper” – he has no such grandson – had tried to use his card at the Apple store, before attacking a security guard and running off.

Mr Harding smelled “a strong rat” and contacted police – but not before he had given “rather more detail then perhaps I should have” to a phony bank worker in a second phone conversation.

Having attended a recent meeting on crime in Hampstead in which residents tore into police for their alleged failings, Mr Harding, 77, was keen to praise officers for their handling of the matter.

“I felt for the police,” he told Heathman.

“I have had quite constructive interactions with them and I thought they needed to be complimented.”