The man accused of murdering New Zealander Cathy Marlow at her London office last year says she was still alive when he left the building.

Michael Fagan told the Old Bailey on Tuesday he tied up Miss Marlow after she disturbed him and a accomplice stealing computer equipment from her office in January 2007.

The body of the 28-year-old Hawke’s Bay woman was found in a shower cubicle at the building in Stockwell, south London. She had been strangled with her own scarf.

Fagan, 33, from Elephant and Castle, southeast London, a former colleague of Marlow, denies murder.

Marlow, a finance manager, had gone in to work on a Saturday as she wanted to get on top of her workload after recently returning from holiday.

Fagan, a married American national, had been sacked from Research Now, a market research company, nine months earlier, the court was told.

He told the jury Marlow had recognised him and started shouting, BBC reported.

After a struggle she had been tied up with a red scarf and a white towel. After cleaning himself up, he went back to see her, the court heard.

“I then went into the hallway where Catherine was sitting, basically to say I was sorry about everything that happened but I am sure if she stayed there she would be all right.

“She was really angry. She was just sitting there and staring and glaring at me.”

Fagan said he left the accomplice named John with her as he left the building.

The case continues.