No wonder Oxford Mail reader Justin Walden thought he was witnessing the filming of a spoof TV show.

He watched in disbelief as a lone security guard, with no protective gear, left thousands of pounds destined for Barclays Bank on a trolley in Cornmarket Street, Oxford, in full view of lunchtime shoppers.

But this was no windup - it was real.

Thankfully, all the passersby on this occasion were honest and didn't take advantage.

This incident may be a one-off, but it is difficult to imagine a more serious breach of security.

Barclays is right to order a full investigation into the lapse and demand assurances from those in charge of ferrying cash from branch to branch that it won't happen again.

It is, after all, the public's money that the bank is supposed to be protecting.

In its advertising, Barclays tells customers that it has "a banking solution to meet your needs".

We hope that doesn't extend to bank robbers.