KEY POINTS:
London police are showing no let-up in their hunt for the killer of New Zealander Catherine Marlow, arresting a fourth man and releasing a detailed timeline of her last day.
As well, Ms Marlow's brother and brother-in-law are flying to London to make a television appeal for anyone with information to come forward.
London police said the fourth man arrested, a 31-year-old, was picked up at a South London address and was being questioned.
Ms Marlow, 28, originally from Hawke's Bay, was found dead at her south London office on January 13. A post-mortem found she was asphyxiated.
London police asked family members to make the appeal from Hastings, to be arranged by New Zealand police.
However, her brother and brother-in-law decided instead travel to London to record the appeal, feeling they could give more information over there, New Zealand police said.
In a press statement, London's metropolitan police Detective Chief Inspector Damian Allain appealed for public help with the investigation.
They had pieced together where Ms Marlow was and what she did in the hours leading up to her death.
"We believe Catherine left her home in Wilkinson St just after 09:00... and walked to work along South Lambeth Rd.
"She stopped at the shop Toni Deli on South Lambeth Rd at approx 09:10 where she bought some food and drink. She arrived at work at approx. 09:30."
She had arranged to meet a friend at 2pm -- an appointment she was not to keep, Mr Allain said.
"Her last known contact was with that friend at 13:36. She was attacked on the ground floor of the building as she was on her way out -- we believe between 13:36 and 14:00."
An eyewitness told police they saw a slim, scruffy white man dumping Ms Marlow's handbag in a rubbish bin on the afternoon of the murder.
A 38-year-old man had already pleaded guilty to the theft of Ms Marlow's credit card and was released on bail, pending further questioning. A 26-year-old man was arrested in South London on January 19. He was released on bail, pending further enquiries.
A 28-year-old man who called police soon after the murder was arrested but later released.
- NZPA
