A woman has been charged with assault by police investigating the disappearance of a Rotorua woman.

Police probing the disappearance of Michelle Hoffman-Tamm were also examining an area of interest between Rotorua and Murupara this evening.

Ms Hoffman-Tamm, 51, was last seen on her red mountainbike on November 7 when she left the Philip Street home she shared with her partner to visit friends.

Police said "significant developments'' in the investigation this morning led police to a rural location close to State Highway 38 between Rotorua and Murupara about 5pm.

The area, and a house in Rotorua, would undergo a forensic examination.

Ms Hoffman-Tamm's bike was found today at a third location in a Rotorua suburb.

A 44-year-old woman would appear at Rotorua District Court tomorrow morning and further charges were likely, police said.

Police wanted to hear from anyone who was in the area of Holland Street between 6pm on November 7 and November 11 and in Victoria Street between November 11 and November 12.

They were particularly interested in the movements of a two-tone light-coloured Subaru Legacy stationwagon between the 7th and the 12th, travelling around Rotorua or between Rotorua, Whakatane and Murupara.

Ms Hoffman-Tamm's family were being kept informed.

Yesterday, which marked two weeks since her disappearance, her sister Jan Donlan made an emotional plea for her "generous" and "good-hearted" sister to come home.

She said the disappearance was completely out of character.

"She's gone off to have a good time sometimes but never anything like this. We've always known where she was," Ms Donlan said.

Ms Donlan said the family, including her sister's two adult children and three grandchildren, were extremely worried.

Police would not comment yesterday whether Ms Hoffman-Tamm had her mobile phone with her when she disappeared but confirmed it had not been used since November 7. He said she was not believed to have had access to any money since that time either.