Woman arrested in SA over missing boy

(AAP) A woman wanted over the alleged kidnapping of a seven-year-old boy from Ballarat in Victoria has been arrested in the South Australian city of Port Augusta, police say.

Victoria Police earlier said they held fears for the boy, identified only as Steven,after 37-year-old Danielle Boundy allegedly snatched him following an argument withhis father.

The father was stabbed.

Ms Boundy was arrested at a hotel in Port Augusta shortly before 8pm (CST) and that the boy was "safe and well", a SA Police spokesman told AAP.

"She has been taken into custody at Port Augusta, and she will be interviewed onsuspicion of committing a serious offence," the spokesman said.

There were no further details about the arrest, he said.

It was unclear whether Ms Boundy would be extradited or charged and remanded in South Australia, Victoria Police spokesman Senior Constable Adam West said.

Steven's father, a 44-year-old Winchelsea man, reported the pair missing to police at 9pm on Wednesday.

Ms Boundy phoned Steven's mother at her Corio home at about 1am advising her she would drop him off at the Winchelsea police station on Thursday morning, but she failed to attend.

"This is the result of a violent domestic involving a knife," Victoria Police Detective Sergeant Gerry Richardson told AAP before the arrest.

"She has then taken off with his son.

"Initially, there was no concern but the return this morning never happened.

"We have serious concerns for the welfare of the child and Miss Boundy ... this is not just a missing person case."The boy's father suffered serious eye injuries after being stabbed by Ms Boundy, whom he met on an internet dating site.

Ms Boundy has a history of mental health problems and has been hospitalised before, police said.