“He is, I would say, a professional burglar, a professional thief,” New York Police Detective Martin Pastor told the New York Daily News last year.

Authorities had arrested Nivelo before, subsequently deporting him to his home country of Ecuador a total of four times.

In November, police released the video footage of the September 29 incident. Guards parked the armoured car along Manhattan’s 48th Street, a crowded area near Rockefeller Centre. While the two guards were distracted and talking by the vehicle’s front, the man struck from the rear.

The precious metal had been sitting unattended in a bucket in the back of a Loomis International armoured truck, its rear doors open wide. The man filched the 20-litre metal bucket out of the back and took off down the sidewalk as fast as he could waddle. He struggled with the gold’s heft for a few blocks while fleeing the scene.

At first, authorities thought the man had fled to Florida. In late December, police said they believed Nivelo was in the Los Angeles area.

Last December, the New York Times reported that Loomis fired the two guards, though the men had been cleared of any suspicion. It was not an inside heist, officials said - just a theft of opportunity.

Police believe the thief did not know at the time what he had taken. Originally depicted as gold flakes, the valuable jewellery scraps were in fact melted into lumpy bars, the Times reported, and kept in buckets for transportation.

A New York police spokesman did not respond to an inquiry Saturday about how authorities had tracked Nivelo to Ecuador or whether they had recovered any of the stolen gold, estimated to be worth US$1.6 million.

Considering the brazen nature of the job, and the stolen goods - a pot of gold - the thief caught a fair bit of attention.

The effort to find the man had been dubbed, reportedly, “Operation Lucky Charm.”