Tiny specks of flesh belonging to murdered teenager Billie-Jo Jenkins were not discovered on her foster-father's clothes during original scientific examination, the Old Bailey heard.

Only after the blood had dried and flaked off was the flesh revealed by fresh forensic tests carried out last year.

The retrial of former deputy headteacher Sion Jenkins has been told that three tiny blood spots on his trousers had been re-examined last year.

Nicholas Hilliard, prosecuting, alleges this showed the stains were made while 13-yearold Billie-Jo was attacked - not when her body was moved by Jenkins, as claimed by his defence.

Billie-Jo was struck on the head at least five times with an iron tent peg as she painted patio doors at the family's home in Lower Park Road, Hastings, on February 15, 1997.

Jenkins, former headteacher designate at all-boys William Parker School in Parkstone Road, Hastings, was convicted of her murder a year later and jailed for life.

However, his conviction was quashed at the second attempt by three Appeal Court judges and a retrial was ordered. Jenkins, 47, denies murder.

Yesterday, forensic scientist Adrian Wain told the jury that Jenkins' trousers were first examined in 1997 and again last year.

The 2004 examination revealed some of the blood spots found on his trousers had white material inside which had not been seen previously .

Mr Hilliard told the court: "In simple terms, we know it was flesh."

The spots were on the lower right leg of Jenkins trousers. They were shown to the jury and judge, Mrs Justice Rafferty, flagged in yellow.

Although the spots were originally identified in 1997, Mr Wain said he thought he knew why the "white material" had not been seen then.

He said: "When the blood dries it flakes off the surface and exposes what is inside.

"In 1997 they were ringed as blood spots.

"In time, the blood has dried and flaked off, leaving what was inside visible."

Four similar spots on Billie-Jo's leggings were also reexamined last year, exposing flesh inside, the jury were told.

When he opened the trial, Mr Hilliard said the defence claimed tiny specks of blood on Jenkins' clothes were caused when her airways were unblocked after he moved her shoulder when he discovered her dead.

But this was disputed by the prosecution, which alleged they were all consistent with being made while she was attacked. The case continues.