Charity boxes belonging to Foyle Search and Rescue (FS&R) have been stolen from several shops by thieves pretending to represent the service.
FS&R Chairman Stephen Twells said that reports from the different premises targeted suggested there was a woman and a man involved in the sham collections.
The money stolen would have gone towards the life-saving work of the charity.
Mr Twells revealed that since January this year, FS&R have pulled 15 people out of the water alive, and helped rescue another 60 people from the river’s edge.
Mr Twells said that the fake collections were something the charity has never experienced before.
“It is frustrating and disappointing to think that a) someone is specifically targeting us, and b) it is also frustrating for the shop keepers who genuinely believed the people were there from Foyle Search & Rescue.
“We are going to have to tighten our procedures now as a result of this.”
Mr Twells said that they were now advising local businesses who display the distinctive orange boxes on behalf of the charity that procedures were being put in place to ensure all members have photographic ID with them when collecting boxes.
He said he was not aware if other charities had also been targeted in this way in Derry.
The shops targeted cover a wide area from Galliagh to Spencer Road,
“This is not young kids, it is grown adults, and they are taking money that people have donated,” Mr Twells said.
FS&R were tasked with providing safety cover during the massive weekend MTV concerts at Ebrington. Mr Twells welcomed the fact that there were no incidents to report.