Isles of Scilly Police are using DNA kits and forensic testing to try to prevent fuel thefts on the islands.
They recently appealed for information after 20 litres of fuel was stolen from the RNLI's inflatable boat on St Mary's.
PC Nic Gould told This is Scilly: "We continue to have thefts reported but thankfully not in the same numbers as previous years. Where it is a viable option we are seizing the fuel caps and having them forensically tested.
"We also have DNA kits which we are using on victims' boats to try to prevent repeat incidents. This is used to mark your property with a UV liquid that contains a unique DNA within it and can be linked to the owner. Other options to catch the offender(s) are also being explored.
"As we have recently stated following the fuel theft from the RNLI inflatable, there will be people within the community who know who is responsible for some, if not all of these thefts, and we ask that if anyone has any information to please contact us, it will be treated in the strictest confidence."
The police described the theft from the RNLI inflatable as "another level", posting on Facebook on June 27th: "It is bad enough that there are people within the community here that are willing to steal from their fellow residents and risk their safety on the water.
"But it is another level when they are willing to steal from a charity where local people risk their lives to save others!
"With the right intelligence from the community we can catch those responsible."
The police station can be reached on 01720 422444. Alternatively, Crimestoppers are on 0800 555 111.
Photo by Lazyblueskies Photography.