Police were questioning a man yesterday about the murder of an academic who died after being strangled and stabbed 49 times.
Barbara Waldron-Johnston, 55, spent much of her career working in biomedical research in New Zealand and had become an expert in cot death and premature babies.
A graduate of Oxford University, she returned to the UK four months ago at the end of a research project and was living alone in a one-bedroom flat in Oxford, where she was found by police last Thursday morning after they were contacted by her elderly parents.
Thames Valley Police, who found her lying in her bedroom with a jumper around her neck, believe she answered the door to her attacker and have not ruled out a sexual motive.
Police were continuing to question a suspect, aged 44, from Faringdon, Oxfordshire, but appealed for further information. They said the attack happened between Monday afternoon and Thursday morning and there were no reports from neighbours of a disturbance and no sign of forced entry at the first-floor premises.
They insisted that Dr Waldron-Johnston's work in animal experimentation was not relevant to their investigation. Weekend reports suggested she may have been targeted by animal rights extremists for her involvement in a research project in Auckland in which scientists caused brain damage in a sheep's foetus and studied the lamb when it was born.
"Part of her work, which involved looking into premature births and cot deaths, involved a small element of animal research," said a spokesman for Thames Valley Police. "However, we do not believe her murder was connected to this and detectives are not exploring this as an option."
Acting Detective Superintendent Steve Tolmie said although the victim was a "private" person, he was hopeful of gaining more clues because she lived among academics in a "tight-knit" community.
"We are still trying to establish information about her lifestyle and would appeal for any people who have had contact or knowledge of Dr Waldron-Johnston to contact us," he said.
"It would appear that she was a private person, having no partner and few known acquaintances. She only returned to this country in September after spending 23 years in New Zealand where she had been living and working. She was not currently employed and was not well-known in the area and we are trying to develop our knowledge of her life."
Dr Waldron-Johnston's parents Anthony, 80, and Valerie, 79, said: "We are all devastated by her tragic and untimely death and ask that our privacy be respected at this terrible time.
"Barbara was a dedicated research scientist who strove to take forward work in the field of cot death and premature babies. She was intelligent, lively and a devoted daughter and she will be greatly missed by us all."Reuse content