Antwerp's diamond trade can never forget last February. A group of burglars pulled off the $100 million diamond heist at the Belgian city's Diamond Centre breaching multiple levels of top security, in what was dubbed the perfect crime.

But the world's biggest diamond heist had just one flaw, which led to law enforcement authorities getting some clues in the case. Yet, despite the suspected mastermind of the burglary in police custody, the loot has yet to be recovered.

A group of safecrackers, burglars, get-away drivers, and other assorted specialists spent two years devising an intricate plan to break into the vault in the diamond trading district, collect the booty and made good their escape. They succeeded, expect one.

The diamond world was astonished by the crime. Investigators have pieced together how the thieves managed to break into one of the world's most secure vaults, but some questions remain: Is the man in police custody the mastermind behind the scheme? And where in the world are all those diamonds? ABC News, which reported extensively on the episode, ran a special show on Thursday, marking one year of the burglary.

A Hollywood thriller: The Antwerp diamond heist reads like a Hollywood thriller. It happened in the Belgian city's diamond district - hub of the world's diamond trade - at the Diamond Centre, the district's largest building, said ABC News.

The burglars systematically took apart all the security measures one by one to get into the main underground vault, where they broke into more than 100 safe deposit boxes full of diamonds and other items, ABC News said.

The heist went off smoothly. ABC News, quoting police, said that at around 7 o'clock in the evening on Friday (February 14, 2003). The next night, Saturday, at least three men took the elevator down to the vault some time around midnight, said ABC News.

"They or other members of the team had earlier disabled a motion detector that was supposed to protect the area, spraying silicone over the sensor, and had taped over a light detector. So the thieves were able to walk around freely. They went to a door next to the vault, broke in and reached for a small metal box, which they knew contained the key to the vault," ABC News said.

Police would not say how the thieves cracked the code to access the vault, but once they did and inserted their stolen key, they faced another even more intimidating obstacle: a last-resort alarm on the vault door, the news agency said.

The thieves, once inside the vault, then broke open a 100 safe deposit boxes, taking what they wanted and throwing other items. The heap of jewels, watches, money that they left behind was worth millions, and police think they only left it behind because they couldn't carry any more, said ABC News.

The thieves then used a homemade key, while leaving, to get access to every door in the building. First they entered an office and stole the videotape recordings from the security cameras. Then, using the special key, they gained access to the building's underground garage, which had an exit opening onto a street outside the diamond district - just one block away from the metal barricades, the round-the-clock guards and the district's police station, said ABC News.

The suspect: The security at the Diamond Centre is extremely tight. Guards patrol the 3-block area of the Centre, metal barricades prevent unauthorized vehicles from entering or leaving, multiple cameras track movements, electronic photographs are taken of every visitor. . . The list goes on.

Yet the burglars managed to get in and away, leading the police to believe that it was an inside job. The cops then zeroed in on one of the Diamond Centre tenants, a one-time jeweler from Turin, Italy, named Leonardo Notarbartolo, said ABC News. He had a background of petty theft and small-time burglaries, and cops believed he could have masterminded the daring operation.

Before the heist, Notarbartolo generally spent only about one day a month at the Diamond Centre, but investigators soon found out that in the week before the robbery, he was at the Diamond Centre every day. Notarbartolo was also one of the last people seen in the vault on February 14, a day before the robbery took place.

The flaw in the perfect plot: Police believe that, before leaving town, the crew gathered at Notarbartolo's Antwerp apartment to divvy up the loot. That afternoon, they headed out of town. About 30 miles south of Antwerp, they pulled off the highway to a remote spot where no one could see them. This was where they made their first, and biggest, mistake, said ABC News.

"Figuring they were safe in the woods, the group left behind bags of trash. But the man whose property they left it on routinely picks up litter, and he soon found the bags containing a glove, some documents, some money and diamond envelopes. Suspicious, he called the police," said ABC News.

However, the bigger break in the case was in a smaller bag inside - a grocery store receipt, a half-eaten salami sandwich and an invoice, torn into pieces, for a shipment to the Diamond Centre. Police pieced it back together and found it was a document referring to Notarbartolo. There also were toll booth receipts dated shortly before the robbery from a highway used to cross the Alps from Italy on the way to Antwerp, as well as cell phone numbers traceable to Notarbartolo and a receipt from a hardware store listing items the thieves left behind in the vault, said ABC News.

The evidence mounted against Notarbartolo, and police soon nabbed him. A week after the crime, Notarbartolo walked into the Diamond Centre acting nonchalant, but the security personnel called police.

Certain that they had nothing on him, Notarbartolo gave them his address in Antwerp, where detectives found his wife and friends packing a car to leave. His apartment, though nearly empty, yielded more evidence: a small diamond found in a rug, a slab of salami and a bottle of wine matching the receipt found in the woods, said ABC News.

Notarbartolo was arrested. A year later, he is still in an Antwerp prison, awaiting trial. Under Belgian law, the maximum penalty he can receive is five years or a few more said ABC News.