Scientists attacked a pig's severed head with a metal bar to simulate the brutal murder of schoolgirl Billie-Jo Jenkins, the Old Bailey heard.

Experts from the Forensic Science Service carried out the beating on the animal's head to work out in which direction blood would spray.

Microscopic pieces of flesh carried by blood spatter were found both on Billie-Jo's leggings and Sion Jenkins' trousers, the court has heard.

Jenkins, 47, allegedly battered his foster daughter to death with an 18-inch iron tent spike as she painted the patio doors of their home in Hastings.

It is claimed the blood spatter found on the clothes of Jenkins shows a "high probability" he was the killer.

Yesterday the jury watched a video of the experiments on the pig's head.

The tape showed scientists wearing white suits, gloves and face masks. One of them was seen to crouch down and beat the head with repeated blows from a metal bar, before studying blood stains left on the floor.

Scientist Adrian Wain told the jury how he took part in the experiments to work out how the 13-year-old died.

Mr Wain told the court: "The purpose was to demonstrate or investigate whether you get differential spatter going forwards and backwards."

Defence barrister Christopher Sallon QC suggested the tests did not accurately replicate Billie-Jo's brutal death on the patio of her home.

He said: "Do you accept there was no circulation in the pig's head, unlike a human head?"

Mr Wain replied: "I think that's obvious."

Mr Sallon said: "This kind of assault produces a lot of blood.

Mr Wain agreed: "Clearly head injuries bleed a lot."

But the scientist said he could not tell how much less blood was involved in his experiment compared with the murder.

Mr Sallon claimed: "The amount of blood used in the experiment was far less than came from Billie-Jo's head."

Mr Wain replied: "I don't think I can answer that question."

He said photos of a pool of blood on a bin liner at the scene were taken hours later, when more of it would have drained out of the young girl's body.

Mr Sallon went on: "The more blood at the scene, the greater the risk the assailant would have blood on his clothing."

Mr Wain said: "No, I don't agree with that."

Jenkins, the former deputy head of William Parker School in Hastings, was convicted of murdering Billie-Jo and jailed for life in 1998 but is facing a retrial ordered by the Court of Appeal.

The court has heard how he lied about his qualifications to get the job, claiming he got ten grade A O-Levels from Gordonstoun College in Scotland.

He claimed he was qualified to teach English but only had a PGCE in PE from Nonnington College in Canterbury, Kent.

Jenkins, whose parents live near Aberystwyth, south Wales, has since married Christina Ferneyhough, 55, a divorcee and former school deputy headteacher.

Jenkins denies the murder on February 15, 1997.