Police have issued advice to car owners in Basingstoke following the theft of nearly two-dozen catalytic converter this month.

Since the beginning of June, Hampshire Constabulary have had 21 offences reported to them. The thefts have been typically happening in the north and centre parts of town and have been occurring during the day time, often in the afternoon, something police say is unusual.

A police spokesman said: "Thieves steal catalytic converters for the valuable metals they can contain.

"Vehicles with a higher chassis are often targeted, as are hybrid vehicles."

The following advice was issued by police

• Park your car in a locked garage where possible, but if this isn’t an option, then park in a well-lit and well-populated area

• If parking in a public car park, consider parking alongside other cars and facing your bonnet towards a wall, if possible

• Avoid parking half on the pavement and half on the road as it makes the underside of your vehicle more accessible

• Look out for people working under cars. If you see anything suspicious, call the police

• If your catalytic converter is ‘bolted on’, you can have the bolts welded shut

• Consider security lighting and CCTV at home

• Identify/etch your converter with a unique mark or serial number

* Cat clamps - a cage that surrounds your catalytic converter to prevent it being unbolted

* Security lighting/CCTV on your drive or covering your parking space

But why are catalytic converters such a hot item for criminals?

Well a catalytic converter contains precious metals which can range from roughly £500 an ounce to more than £4,000, depending on the metal being sold.

A catalytic converter is found in a box on the car's exhaust system and is used to clean up exhaust gases before they're expelled from the exhaust pipe.

Hybrid cars are targeted by thieves more often than others because they have two power sources – an electric motor and a petrol or diesel engine.

As a result, their catalytic converters are used less frequently to process pollutants and the metals inside them are less likely to corrode which then sustains their value.

If you see something you believe to be suspicious, call 101. You can also report online via our website www.hampshire.police.uk.

If you believe a crime is in progress, always call 999.