A man who has taken his seven-week-old baby from a Canberra home has been urged to contact police.

Police say Garry Gorden and his baby son left a house in O'Malley early on Sunday and they believe they may be heading interstate.

The matter is no longer considered an abduction, however police are concerned about the welfare of the baby boy.

Police said the baby was being cared for by relatives and the child's removal is out of character for Mr Gorden.

"The safety of the baby is our first priority," Superintendent Brett Kidner said.

"Garry, we urge you to contact us as soon as you can so that we know you and your baby are alright.

The 25-year-old is described as 193cm tall, 140kg, with short, curly red hair.

He may be driving a 1993 grey Ford Falcon sedan with number plate YEB47J or a white Mitsubishi Magna Solara 2001 ACT plates YBR67P.

Anyone who sees Mr Gorden is urged to call police on 131 444, but not to approach him.

© AAP 2014