Animal rights activists have reacted with fury after it emerged that researchers in China have been using live pigs as crash test dummies.

Fifteen immature pigs were strapped in for high-speed simulations in a test which killed seven of them immediately.

The animals were denied food and water for hours before the tests and suffered a range of injuries including bleeding, laceration and internal bruising.

Pigs and other animals were previously used in crash tests in the United States but the practice was ended in the 1990s.

Strapped in: A young pig is fitted into a car seat in a crash test in China where researchers used the animals to mimic six-year-old children in 30mph smashes

Test subjects: Fifteen immature pigs (two of which are seen above) were strapped in for high-speed simulations in a study in China which killed seven of them

Today Zachary Toliver of animal rights group PETA took aim at what he called a 'cruel' and 'unjustifiable' practice.

'Despite the existence of sophisticated animal-free models, experimenters continue to fasten abused, frightened animals into car seats and crash them into walls until their bodies are bloody, bruised, and mangled,' he said.

'Live pigs are pulverised in these tests, leaving them with broken bones and severe internal injuries before they're killed and dissected.

'Pigs don't naturally sit up in car seats. Their anatomy is also very different from that of humans, so the data obtained from these horrific animal experiments aren't applicable to human car-crash victims.

'Car companies figured out years ago that these kind of experiments are worthless and tell us nothing about a human experience in a car crash.

'Using sentient animals in car-crash tests is cruel, archaic, and unjustifiable.'

PETA said it had written to the Institute for Traffic Medicine in China to urge them to stop using live animals.

Researchers justified the use of immature pigs by saying their anatomic structure was 'similar' to that of human children.

The pigs were intended to 'mimic children of six years old', they explained in their paper in the International Journal of Crashworthiness.

The scientists insisted they had followed U.S. guidelines for the use of laboratory animals and said their study had been approved by an ethics committee.

In the experiment, fifteen immature pigs were strapped in with various kinds of seatbelts and subjected to high-speed testing at up to 30mph.

Impact: One of the pigs is flung forward by the simulated crash in a research experiment in China which animal rights groups have condemned as 'cruel'

Testing: These black-and-white images show two of the pigs during the crash tests in China which researchers said were intended to help develop seatbelts for children

The animals were positioned in a seat which was mounted on a sled and slammed into a wall.

The pigs were between 70 and 80 days old, and were given no food for 24 hours before the experiment.

They were also denied water for six hours beforehand, but were given an anaesthetic to reduce 'excitement and stress'.

'Of the tested animals, seven died immediately after the impact, and the rest survived six hours after the test,' scientists said.

After the tests, experts carried out detailed 'necropsies' to determine exactly how the pigs had been injured and killed.

'The common injury types included abrasion, contusion, laceration, bleeding and fracture,' they added in the study which was published online earlier this year.

PETA staged protests in America which prompted General Motors to announce the end of animal tests in 1993.

'It's horrifying to look back now and imagine that animals were deliberately slammed into walls at high speeds in car-crash tests,' the animal rights group said.

The company admitted it had used thousands of dogs, rabbits, pigs, ferrets, rats and mice in its laboratories in the previous 10 years.

Modern crash test dummies are highly advanced and can cost hundreds of thousands of dollars.

Fitted with data recorders that measure the impact of a crash, dummies have also been adapted to larger shapes and sizes to reflect the modern population.