Christchurch police are still seeking a woman who came to the aid of a distressed female early on Sunday.

Detective Tim Cummins said the woman was driving alone in a white Subaru legacy car when she stopped to help a distressed female near the intersection of Barbadoes St and Nova Pl between 1am and 2am on Sunday.

The woman she helped had been the victim of an assault in the area shortly before the driver found her, Cummins said.

The victim was a 30-year-old Christchurch woman. She had not suffered any physical injuries, but was visibly distressed following the attack.

Cummins said police believed the assault was an "isolated incident'', but he could not say whether the man was known to the victim as the case was now before the courts.

A 42-year-old man was arrested in connection with the incident and appeared in the Christchurch District Court yesterday.

He had been charged with assault with a weapon and attempted rape and was remanded on bail to August 13.

Cummins said police were "anxious" to speak to the driver who came to the victim's assistance.

She was described as European, of slim build and with short blonde hair.

The driver, or anyone with information, is asked to contact Detective Tim Cummins at New Brighton police on 03 373 9160.

- © Fairfax NZ News