A Mosquito which can carry a host of deadly diseases has entered Britain.

Two Asian tiger mosquitoes, which can transmit up to 23 infections - including West Nile virus and dengue fever - were found in a suburban back garden.

Illnesses passed on when the insect bites humans include a parasitic worm which can cause serious breathing complications.

The species is normally found only in the forests of Asia, Africa and South America.

Britain has been invaded by the Asian tiger mosquito which carries potentially-fatal diseases

But after its discovery in Gloucestershire - the first sighting in Britain - experts fear it may have settled here permanently.

The mosquito, which has yellow stripes, is believed to have entered the UK on container ships and then thrived in this year's wet summer.

The insects were spotted at a house in Cheltenham by resident Julian Berryman.

The 41-year-old said: "I have seen tiger mosquitoes when I travelled around Europe and thought this looked like one.

Arran Dzendrowski spotted the striped mosquitoes on a wall in his grandmother's back garden

"They are very big mosquitoes and the most ferocious going."

Because the Asian tiger mosquito lays its eggs in water it is feared they were surviving in small pools that collect in the bottom of tyres sent to Britain on container ships from Asia.

The insect is particularly dangerous because, unlike other mosquito species, it bites in the day and not just in the evening.

West Nile virus, which has killed hundreds in mainland Europe and North America, lives mainly in birds, but can be passed to humans when they are bitten by a mosquito which has already bitten an infected bird.

Dengue fever, which is most common in Africa, India and the Far East, can also prove fatal.

Symptoms include a sudden high fever, painful aches in the bones, joints and muscles, and a rash.

Asian tiger mosquitoes were first reported in Europe in 1979, in Albania and Italy in 1990.

More recently they have been seen in France, Belgium, Montenegro, Israel, Switzerland and Spain, but there have been no recorded sightings from the UK.

Clive Salisbury, pollution control manager for Cheltenham Borough Council, said the mosquitoes found in the town had been sent for final identification.

He said: "Although it appears to be warm enough for them to survive over here, it's not thought to be hot enough for the diseases they carry in countries like Africa to survive in the UK."

The Health Protection Agency said: "In certain parts of Europe where the species can be found they are not able to carry any viruses."