A man has been charged with the murder of a missing nine-year-old girl.

Detectives arrested Justin Stein, 32, at a unit in Surry Hills last night after the child went missing from the Blue Mountains on Friday, January 14.

Police Divers, Hawkesbury Police Area Command, Public Order and Riot Squad (PORS), Operational Support Group (OSG) and Police Rescue Squad conducted a search in the vicinity of the Colo River.

The body of the child was located in a barrel.

She cannot be identified for legal reasons.

Police will allege Mr Stein was dragging the barrel toward the river but couldn’t get through heavy bushland.

It is also alleged he went to a hardware shop to buy several 40-kilogram sandbags before attempting to launch a boat.

He appeared briefly in court this morning via a visual-audio link from the Surry Hills Police Centre where he did not apply for bail.

He will be taken to Silverwater Prison where he will spend 14 days in quarantine with his next court appearance scheduled for March.

Press PLAY to hear more from Sydney Morning Herald crime reporter Sally Rawsthorne below 

Press PLAY below to hear Ben Fordham break the news of the arrest

Criminal Psychologist Tim Watson Munro told Ben silence from the police during the investigation gave a huge clue.

“The media play an invaluable role in assisting in solving these cases, the fact that this wasn’t being put out there suggests to me that the police has information, they were playing the cards pretty close to their chests.”

Press PLAY below to hear the full interview

Image: Nine News