Image copyright RSPCA Cymru Image caption The Green Balkan lizard, about 20cm (8in) long and not dangerous, shed his tail - a common defence mechanism - after being discovered in June

A 20cm-long lizard was among the exotic animals that accidentally sneaked into the UK inside holidaymakers' suitcases, a list issued by the RSPCA reveals.

One surprised Briton found an anole lizard had made a 4,200-mile trip from the Caribbean to Wickford, Essex, and a South African scorpion arrived in Kent.

A frog this year went from South Africa to Nottinghamshire and a bright green Balkan lizard swapped the sunny Greek island Kos for Bridgend, south Wales.

The creatures have since been re-homed.

The RSPCA said they had been sent to zoos, wildlife parks, or specialist keepers.

Image copyright RSPCA Image caption This frog made the 8,000 mile trip from South African to Nottinghamshire in January

It is illegal to allow non-native creatures to escape into the wild in the UK.

Conservationist Jim Foster, from the Amphibian and Reptile Conservation Trust, says that doing so could "theoretically" threaten native-British populations.

"Sometimes they do get out and into the wild but typically they won't survive very long. It's simply just too cold and the animals will die in a matter of days or weeks," he said.

Image copyright RSPCA Image caption An olive thick tail scorpion who travelled from South Africa to Kent in April.

The population is also likely to be limited by the fact that most animals brought in accidentally inside a suitcase will be on their own, without a mate to breed with, Mr Foster added.

But he warned that there is "a potential risk regarding the transfer of disease" which are not found in the UK.

The RSPCA advises people not to handle any animal that has been accidentally imported and to treat it "with caution until identified accurately".

RSPCA's head of wildlife said "Our message to holidaymakers at this time of year is to take care when packing to make sure there aren't any unwelcome travel companions stowing away in clothes, shoes, towels or bags, and once packed, keep your bags zipped up.

"Don't leave your bags open on the floor overnight as this also provides an opportunity for animals to stow away."

Image copyright RSPCA Image caption The two inch-long lizard was unwittingly brought back to Essex by a family who had been on holiday in St Lucia

Among the creatures to have settled in Britain after being accidentally brought to the island is the midwife toad.

At the start of the 19th Century it was commonly found on mainland Europe but within 100 years had successfully settled in Britain.

More recently, conservationists reported capturing four Italian wall lizards in Buckinghamshire in 2012 after they had been accidentally brought in inside imported stone.

Stowaway animals: What is the law?

In the UK, you can be fined or prosecuted if you: