The claim is made in a new report from Traffic, the wildlife trade monitoring programme.

The group says the gangs, including the Russian mafia, are making huge profits from the activity, which threatens many endangered species.

"The profits, sometimes worth up to 800%, combined with the low risks of detection and lack of serious punishment make illegal wildlife trade very attractive to criminals," said Stuart Chapman, WWF-UK Head of Species Programme.

Traffic says the present laws are very slack and criminals breaching them are not punished at all severely.

The group is encouraging the British public to write to their local MPs expressing their wishes for more strict laws and law enforcement.

Animal guards

Not only are endangered species being smuggled from country to country dead and alive, but they are also being used to guard and conceal drugs, says Traffic.

Drugs are being exchanged for exotic birds

One shipment of boa-constrictors was searched and it was found that each snake had condom-wrapped pellets of heroin inside its gut.

The packages had been inserted through the rectum which had then been sewn up. All the snakes died.

Another incident involved some venomous snakes guarding a package of heroin which was hidden in their cage.

The snakes were acting as a deterrent to put security guards off searching the cage.

Money laundering

Rare and valuable animals are being used as a currency by the smugglers and are often directly exchanged for drugs.

For example, Traffic says, "plane loads" of smuggled birds from Australia have been exchanged for heroin in Bangkok, with the drugs being flown back to Australia for sale.

Some of the animal smuggling organisations are used as a front to launder money from drugs sales.

All of these animals are rare and valuable, and by smuggling them out of their native countries their safety is being further jeopardised.