Matthew Fagan, a former colleague, is on trial for murdering Hawke's Bay-raised Ms Marlow in January last year.
London's Old Bailey Court was told the 28-year-old finance manager was killed by Fagan after she went into work at market research company Research Now on a Saturday to catch up after a holiday.
It was alleged that Miss Marlow disturbed Fagan's theft of computer equipment from the company.
The jury was told that she had been strangled with a red scarf knitted for her by her mother and her body dumped in a shower cubicle.
Fagan has admitted theft from the workplace but denies murder.
Miss Marlow's flatmate, Rachel Warren, raised the alarm after Miss Marlow failed to meet her at a nearby supermarket only hours after she had made the appointment.
Ms Warren told the court she began to feel "uneasy" after Miss Marlow failed to turn up and was not picking up her phone.
Ms Warren called friends to see if they had heard from her and began a frantic search to try and find her.
She even begged staff from the shop where they had been due to meet to let her watch CCTV footage to see if she could see any trace of her flatmate.
Her body was found by friends who had gone to look for her at the company premises.
Miss Marlow had lived in London for three years before her death in what police described at the time as a "frenzied attack".
Fagan, 32, originally from the United States, has been in the UK since 2000 but only worked at Research Now for a year before he was sacked.
The trial continues.
