Schoolgirl Billie-Jo Jenkins clung on to life for several minutes after her head was battered with an iron tent spike, the Old Bailey heard.

The 13-year-old suffered fatal head wounds while she was painting the patio doors at her family home in Hastings.

Her foster father Sion Jenkins, 47, is said to have murdered her after losing his temper with her.

Billie-Jo was hit at least six times with the 18in peg, and some of the blows fractured her skull and revealed her brain.

But the court heard yesterday she would not have died instantly.

Professor David Menon told the jury: "I think if someone had severe head injuries, especially if the skull is open, they cannot survive for very long."

The scientific expert, giving evidence via video link from Australia, added: "I think certainly it would be minutes but I wouldn't like to put a figure on if it was much longer."

The court earlier heard that Billie-Jo would have been unconscious in the minutes before her death.

Former deputy head teacher Jenkins was convicted of murdering Billie-Jo at their home in Lower Park Road, Hastings, and jailed for life in 1998.

But he is now facing a retrial ordered by the Court of Appeal.

The court earlier heard how he was worried about his false CV application for the headteacher's job at William Parker School in Hastings.

Jenkins denies murder on February 15, 1997.