KEY POINTS:
A man who may have been one of the last people to see Christchurch prostitute Mellory Manning alive has come forward and spoken with police.
Detective Inspector Greg Williams said the man provided a statement which "adds to the information we are now building up".
Police had been seeking the man after a sex worker said he had approached her on January 2 wanting to talk about Ms Manning's death.
It was thought the man had been parked near the spot where Ms Manning had been standing around the time of her disappearance.
The 27-year-old's body was pulled from the Avon River three weeks ago.
She had been strangled, stabbed in the chest several times and beaten about the head and legs with what appeared to be a piece of reinforcing steel.
Mr Williams said it appeared Ms Manning had been picked up from the corner of Manchester and Peterborough streets at 10.45pm on December 18 and attacked shortly after.
Her watched stopped at 10.58pm and text messages sent to her at 11.30pm received no reply.
"This all infers that the violent attack on Mellory that evening was within a very short time frame," Mr Williams said.
"We also know that there would have been considerable blood loss at the point where she was attacked or in any vehicle that she would have been carried in, or onto anything that she might have been wrapped in.
"Again I remind the public to think about people they know who were out and about on the night of the 18th of December, whose demeanour might have changed, who are reluctant to use their vehicle, have suddenly sold it or said it has been stolen, have cleaned their vehicle or made any alterations to it."
He said investigators had identified more than 140 prostitutes who worked around Manchester St as well as about 40 "minders".
"It has been a huge task tracking these people and talking to them but we have gained some great information about incidents occurring both before and after the murder."
There were still several people police wanted to get hold of.
The driver of a Ford XR6 or XR8 which Ms Manning was seen getting into has not been identified, although a number of men who used prostitutes and drove a similar style car had been "nominated", Mr Williams said.
A group of men in a dark coloured four-wheel-drive with tinted windows and chrome wheels was also seen in the area, as was a "rough looking" man with grey stubble who drove a blue four-wheel-drive and approached one of the prostitutes at about 10.35pm asking for prices.
Mr Williams asked those people to contact police.
- NZPA