Fighting back tears during an appeal, Johann Morgan's sisters and four children begged for public help to find the mother, grandmother and sister who disappeared without a trace more than two weeks ago.

"If anyone has seen my sister please let us know," a visibly distraught Vivienne Morgan said of her sister on Monday.

"My brothers are so worried, please come home sister ... please bring my sister home."

The mother of four has not touched her bank accounts or used her phone since August 8.

A police breakthrough late last week found a car, believed to have been used by Ms Morgan burnt out, 17 kilometres from town on the Oxley Highway.

Now, Strike Force Chiltern has been set up with a team of 15 Oxley detectives, police as well as investigators from the State Crime Command's homicide squad.

A forensic search of Ms Morgan's home has been carried out as well as of the burnt out car.

"Please bring my mother home please, my family is very worried," son Michael Morgan said yesterday.

"If anyone has seen or heard of my mum's whereabouts, can they please contact Tamworth Police Station ASAP."

The family, who put up missing persons posters around Tamworth, are struggling to come to terms with the disappearance and are searching for answers.

"It's been very hard not knowing and not knowing her whereabouts and wondering where she is," sister Yvonne Morgan said yesterday.

"We used to talk, she would ring up everyday, and speak to one of us.

"They're doing no good, we just want her back, so if anyone has seen or heard from her, please contact Tamworth police to get her home. The kids need her and the grandkids."

The family said Johann was a caring and loving mother, who would always take her phone and be in contact.

They searched everywhere for her, and called extended family across NSW before reporting her missing on August 16 - a week after she was last seen.

"We need help, we need to find out sister," Yvonne said.

"She would always have her phone, ring one of us or ring one of her kids about where she's going or what she's doing, or who she's with.

"She was lovely, exciting, beautiful, a beautiful lady, loving person, loving mother, loving grandmother, loving sister."

Police would not say whether Ms Morgan met with foul play but investigators say there is something very suspicious about the 40-year-old's disappearance.

They said that's why homicide detectives have joined the investigation over the weekend and, now, strike force police are probing the last moments Ms Morgan was seen in the Coledale area on the weekend of the 8th of August.

"This is a missing person investigation, and it's an extensive one, however, under the circumstances with no activity on Ms Morgan's bank account or phone, we're concerned for her welfare," Oxley crime manager Inspector Phil O'Reilly said yesterday.

"There are a large number of people that have been interviewed and are assisting police with their enquiries."

Police won't comment on what forensic investigators found inside Johann's home during a search on Friday, and they're still waiting on the forensic evidence taken from a burnt out car, found in a quarry, off the Oxley Highway.

The white early-model Mitsubishi station wagon - which belongs to one of Ms Morgan's extended family members - was found burnt out on August 10, but investigations last week only revealed Ms Morgan had access to the vehicle around the time she disappeared.

An air search of the area of between Coledale and Bective has been conducted, as well as a search where the vehicle was found, but police are no closer to finding the missing mother-of-four.

"There are more statements that our investigators are taking but we hope though that someone from the community does have information that can assist us and give us some other avenues of investigation," Inspector O'Reilly said.

"The last time we believe Johann was seen was on the 9th August in West Tamworth near her home, so if anyone has seen Johann, it might have been in West Tamworth, or in connection with a white Mitsubishi station wagon which we now know was located on the evening of the 10th of August."

Northern Daily Leader