NEW YORK (REUTERS, AFP) - New York police are searching for a green-clad man who swiped an 86-pound (39kg) pail of gold flakes off an armoured truck two months ago and disappeared with the estimated US$1.6 million (S$2.3 million) in treasure.

The city's police department late Tuesday released photos and video of the suspect, who was lingering near the truck on the afternoon of Sept 29 and took advantage of a moment of distraction by its security guards to snatch the five-gallon (19-litre) bucket.

But surveillance footage showed the brazen sneak making a quick getaway on foot though the crowded late afternoon streets of midtown Manhattan in late September, amid oblivious commuters.

The video shows him walking with some difficulty, likely due to the weight of the bucket.

The theft happened on a busy stretch of 48th Street in the borough of Manhattan, near the Rockefeller Center office and shopping complex, police said.

On Wednesday, police urged anyone who recognised the 50 to 60-year-old man - seen head-on but slightly indistinctly in the newly released footage - to come forward and identify him.

It was not immediately clear if the man knew what he was stealing, having crossed the street behind the open back of the unguarded armoured security truck before changing tack and helping himself.