KEY POINTS:
Police are looking into problems missing Christchurch woman Tisha Lowry had with her boyfriend.
Ms Lowry, 28, has been missing for more than a week and police and her family have fears for her safety.
Her disappearance remains a "missing persons" inquiry, but police say they are following a "homicide procedure".
Ms Lowry had been living with her grandfather in Christchurch "to have a little bit of space" after moving to the city from Porirua with her 48-year-old boyfriend a year ago.
Detective Senior Sergeant Virginia Le Bas said Ms Lowry's boyfriend of about five years was part of the inquiry, and was co-operating.
Problems between the pair were also part of the investigation.
"They clearly have had differences at different times. But I'm not aware of anything in recent times. Everyone has differences at times, they might have problems in their relationships - it's what other people are saying. We can't speak to Tisha at the moment to ask her."
A "natural conclusion" could be drawn that she was seeking some time away from the relationship.
Ms Lowry was last seen visiting a bar in the eastern suburbs with her grandfather and then walking home, possibly carrying a box of beer. It is believed she arrived home and changed her clothing. She had only the clothes she was wearing, and had left her handbag and cellphone at home.
Police are also searching public areas nearby including a river. Up to 45 officers are involved in the inquiry.
Ms Le Bas said the public response had been limited, and some people might be hesitating to come forward with information.
