Ammanford hairdresser Kelly Hyde may have lived for as long as two hours after the fatal attack she suffered first began, a jury has been told.

Home Office pathologist Dr Andrew Davidson told Swa-nsea crown court how tests showed the 24-year-old could have survived the initial assault, which culminated in at least 20 separate injuries to her skull.

Dr Davidson said that minor cuts and bruises to Miss Hyde's arms may show that she attempted to fend off her attacker and prevent further impacts to her head and face.

Dr Davidson said expert opinion differed on the length of time the victim may have survived, but in his view, the period would have been between one-and-a-half and two hours. He told the court how he attended an area off the Pantyfynnon bridle path at 3.05pm on September 30 with crime scene investigators and saw Miss Hyde's body floating face down in the nearby stream.

When he examined Miss Hyde's body at the University of Wales Hospital, Cardiff, Dr Davidson discovered "abundant haemorrhaging on the underside of the scalp linked to outer injuries".

He described in detail to the court the multiple fractures found to Miss Hyde's skull and jaw bones, which he said caused her death.

"There was evidence of blunt force trauma, and that was principally to the head," Dr Davidson said.

"There were 11 contusions of the face and nine of the scalp, along with bruising and some abrasions.

"The head injuries were consistent with multiple blows with a blunt weapon. The head injuries would be enough to kill."

He told the court that in his opinion, Miss Hyde's injuries were not consistent with a fall or with collisions with rocks in the water.

He also described how Miss Hyde's lungs showed some signs of water inhalation, but it would be impossible to prove whether she drowned.

He also told the court the machine marks found on a dumbbell discovered near the scene matched marks left on Miss Hyde's head and scalp during the attack.

A 17-year-old from Ammanford who cannot be named for legal reasons, denies murder.

The case continues.

For full trial reports, see today's Guardian