The owner of a local shop has warned businesses to be on the alert after he received this  fake £20 Isle of Man note, above, and a £50 note taken out of circulation after the Northern Bank robbery in 2004.. And more worryingly, the Andersonstown shopkeeper says the fake note, purporting to be issued by the Isle of Man Government, passed unnoticed by a counterfeit detector pen.

Later that week he was again caught out when a Northern Bank note from the batch that was withdrawn in the wake of the 2004 £26m heist was also passed in his shop.

The local businessman says  the Isle of Man notes are flooding the area and he has advised already hard-pushed business owners to remain alert in light of the incidents. We’ve been told that £500 worth of the Isle of Man notes can be bought locally for £100.

“This Isle of Man note was passed in my shop, it got by because the counterfeit detecting pen and machine don’t work on them. I’ve warned everyone I know about them, including other shops, but people need to be aware, these things are total fakes.

“Later in the same week, a girl passed one of the £50 purple Northern Bank notes that were taken out of circulation because of the robbery. I checked it out online because I recalled something about it and found out it was part of that batch that was taken out of circulation.

“People need to be careful, if they have hit my shop, they will no doubt hit the rest of the shops on the road.”