A water spray with its own unique 'fingerprint' is the latest weapon used by Sussex Police in the war on car crime.

The force revealed its new Smart Water device in Hove yesterday.

Smart Water is a clear fluid that only shows up under UV light. Each batch of the liquid has its own traceable identity, similar to DNA.

Officers in Brighton and Hove are to place "trap cars" in crime hotspots in the city.

Anyone breaking into the vehicles will be sprayed with Smart Water hidden in the cars.

The device's spray gun is triggered when an item inside the vehicle is pulled or moved.

The device is small enough to be hidden and thieves may not even realise they have been caught.

But the liquid leaves a mark on clothes and skin.

Police patrols will be in high crime areas with hand-held UV scanners to examine anyone acting suspiciously.

Each batch of Smart Water can be traced back on a database through the forensic science laboratory.

Crime prevention officer PC Chris Knox said: "The cars will be deployed around Hove, where the crime problems are.

"If we see anyone acting suspiciously, we will run the scanners over them. If they glow, we will arrest them.

We are going to be using them a lot more in the coming months."

PC Knox added: "We don't want car crime and if no one attempts to steal the cars or their contents then that's good.

"Anyone we arrest will be given information about Smart Water. We want to educate people about it.

"It has already won a Prince's Trust Award. It is very clever and will be used more and more by police."

Posters warning about crime will be put up in hotspots as part of the campaign.

Smart Water, developed by a European company, can also be used to mark property and can be sprayed on burglars when house alarms are triggered.