Police are urgently looking for a 13-year-old boy who has been missing for more than a month.

TJ Biddle Bockman was last seen on State Highway 38 at Murupara, east of Taupo, on January 11.

Police believe he may be in the Rotorua area.

Detective Senior Sergeant Greg Standen, of eastern Bay of Plenty CIB, said TJ's family had been spoken to extensively since he went missing.

"Unfortunately those enquiries have now been exhausted and we are asking for the public's help to try and locate TJ.

"We do have concerns for TJ's safety and wellbeing. He does not have a source of income and is at risk of harm," he said.

He is Maori, of average build and about 165cm tall.

Anyone who has seen TJ or knows where he is should contact police.