On Monday, Johann Morgan's four children and two sisters urged anyone who might have seen their mother to contact police as homicide detectives joined the search for the missing 40-year-old.

"Please I just want my sister back," Vivienne Morgan said.

"Please come home, the family is very worried."

Oxley detectives have launched Strike Force Chiltern, with assistance from homicide detectives from Sydney, to investigate the disappearance.

On Monday, police confirmed a burnt out car, which Johann might have been using, had been found about 17km out of Tamworth on the Oxley Highway.

The white early-model Mitsubishi station wagon was abandoned and torched on August 10 but Oxley crime manager Inspector Phil O'Reilly said investigations had only revealed connections with Ms Morgan's disappearance late last week.

The vehicle has been forensically examined and has been seized by police. 

Inspector Phil O’Reilly said detectives hold grave concerns for her welfare.

“Investigations have revealed Ms Morgan left home without her wallet and mobile phone, and has not accessed her bank accounts since her disappearance,” Inspector O’Reilly said.

Ms Morgan is described as Aboriginal in appearance with olive complexion, about 165cm tall, dark hair and a medium build.

Anyone with information should contact Tamworth police on (02) 6768 2999.

Full details in Tuesday's edition of The Leader.