Sex assault suspect found, but woman still missing

Malcolm Chaston (aka Maniapoto Walker) and Vanessa Pickering. Photos / Supplied

Police have found a man wanted over an alleged sexual assault but not the missing woman believed to have been with him.

Grave fears are held for Vanessa Anne Pickering, 27, the mother of a seven-year-old girl, who has not been seen or heard from since leaving her home in Christchurch on Monday evening. Whether she is still alive is "undetermined", police say.

She was thought to be with Malcolm Chaston, also known as Maniapoto Walker, who was wanted for an alleged sexual assault on the day Ms Pickering went missing - though this allegation does not relate to Ms Pickering.

Detective Senior Sergeant Virginia Le Bas said police located Malcolm Chaston in the Cheviot area around midday.

Ms Le Bas says his vehicle was stopped using road spikes and he did not resist officers. He was driving the Toyota Estima police were seeking.

Some 60 police officers are continuing to search for Ms Pickering in the coastal area of Banks Peninsula, including searches of the water.

Ms Pickering's daughter was with her when she left on Monday, but has since been dropped off and is in the care of other family. The daughter was "quite traumatised by the situation", said Ms Le Bas.

Ms Le Bas earlier said it was "very unlikely" that Ms Pickering went with Chaston voluntarily, given the time that had passed.

"The fears are grave in that there has been no contact with Vanessa. There's been no cellphone contact, she hasn't been in contact with her daughter or anyone else in her family, and this is highly unusual."

She said police thought there was "a sighting or a belief that she's been in and around" the Banks Peninsula area.

Ms Pickering does not currently have a cellphone, being "prone to losing them".

Ms Le Bas said Ms Pickering and Chaston met through a work association and "know of each other", but police did not have any knowledge of a friendship or relationship between the pair.

Ms Pickering has blonde hair, and was wearing trousers and a brown jersey.