Missing boy triggers first ever ACT 'amber alert'

Police are searching for a 6-year-old Canberra boy who has been missing for six days.

Phoenix Mapham Source: ACT Policing

Police in the ACT have issued their first ever amber alert amid "serious concerns" for a missing 6-year-old Canberra boy.

Phoenix Mapham was last seen being driven by a woman suspected to be his mother, Tessa Woodcock, about lunchtime on Thursday.

Authorities say the mother has not been granted custody of the boy. 

"Phoenix is not in the lawful custody of his mother and police are seeking to locate him as there are serious concerns for his wellbeing," ACT Policing said in a statement.

"The pair is believed to be in either the Australian Capital Territory or New South Wales."

An amber alert is used in "time-critical" cases where police have serious concerns about the safety of a child and need assistance from the public.

Phoenix Mapham's mother, Tessa Woodcock. Source: ACT Policing

Phoenix and the woman believed to be Tessa Woodcock were last seen in a white 1999 Holden Vectra with registration YAU56P and could also be travelling in a blue Subaru Forester with a possible registration YKP08U.

Police have asked anyone with information to contact them on [phone] and quote reference number 6300755.

Police say information can be provided anonymously.