The bodies of two people, believed to be a mother and son, have been found in a pond in the outskirts of Canberra.

Police are now searching the area for eight-year-old boy Pranav Vivekanandan, after expressing "serious concerns" for his welfare.

"While an extensive land and water search for Pranav has been underway since the discovery of two bodies in Yerrabi Pond this morning, police and family are issuing this plea in the event that he is alive and someone knows his whereabouts," ACT Police said.

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Pranav is described as being of Indian Sub-Continental appearance, about 110cm tall, with short dark hair, and dark brown eyes.

He may have been wearing an orange T-shirt and light-coloured shorts, and a jacket.

ACT Police were given reports of a body in Yerrabi Pond, in the outer Canberra suburb of Gungahlin, at about 8am on Saturday.

When maritime officers from the Australian Federal Police arrived at the scene, they found the two bodies of the woman and boy. 

Police and State Emergency Service volunteers were initially searching the pond and nearby parkland for a missing girl.

They later clarified they are searching for a missing boy.

"It's obviously a tragic situation, it's still very early days and it's unfolding," Detective Superintendent Hall O'Meagher said.

"We're making inquiries with the family of these deceased people.

"They're assisting us with our inquiries at this time.

"Our thoughts go out to them and also to the responding police who have had to deal with this tragic circumstance."

Police will prepare a report for the coroner.