The Hatton Garden leader, known as "Basil," has been imprisoned for ten years – four years after he made the $ 14 million robbery.
The alarm specialist Michael Seed, 58, was probably involved with a key phrase in the building in the London Diamond District before he defeated the security system.
He was one of two men who had climbed into the vault to plunder 73 lockers after the group of aging criminals had drilled through the thick concrete wall during the Easter weekend of 2015 on the Easter holidays.
Seed, who pays no taxes, does not claim benefits, and rarely uses a bank account, was arrested for three years before police raided Islington, north London, about two miles from Hatton Garden, on March 27 last year conducted.
After being convicted and sentenced on Friday at Woolwich Crown Court, Judge Christopher Kinch, QC, told him, "Your role has been central. They were at the heart of the core activities that needed to be done.
"They were not just there to pick up and carry. In my opinion, this is one of the worst offenses of its kind. "
Seed, a light blue pullover, glasses, and gray hair with thinning hair, looked expressionless as he was locked up.
The electronics expert confidently told a jury at Woolwich Crown Court that he was not the man who was called "Basil" by the rest of the gang.
However, he became the tenth person to be convicted in connection with the crime when he was convicted of plotting the Hatton Garden Safe Deposit Company's conspiracy and the conspiracy to settle the proceeds after having found in his bedroom gold ingots, gems and Jewelry worth 143,000 pounds sterling was found.
According to the court, of the £ 13.6 million stolen in the robbery, only £ 4.5 million – about a third – was recovered by the police.
Seed was released from the conspiracy to blow up the high-end jewelry store Chatila on Bond Street at the end of the bank holiday weekend in August 2010 along with members of the same gang.
The prosecution had claimed that he had pretended to be a BT engineer before the intrusion of the security system and then used a 2G cell phone to block the alarm.
The thieves could not drill into a vault containing 40 million pounds worth of gems, but worth £ 1 million worth of jewelry from the showcases at the store.
The jury, consisting of six men and six women, consulted 35 hours and 35 minutes before returning their sentences.
Well-spoken Seed, who grew up in Cambridge, was imprisoned for 10 years on charges of Hatton Garden and eight years in conspiracy to convert or transfer property crime.
Seed's two Hatton Garden ringleaders, Brian Reader, 80, John Kenny Collins 78, Daniel Jones 64, and Terry Perkins, who died in prison at the age of 69 last year, were all imprisoned in 2016.
Collins and Reader are already released from prison, but face imprisonment if they can not repay more than 6.5 million pounds of the proceeds, which the police believe could still be under their control.
Detectives believe that the gang could have operated undetected for decades before they were captured, but it can not be linked to other crimes.
Seed traveled abroad three times after being photographed by a surveillance team for the first time in the weeks following the Hatton Garden collapse when he was unknown to the police.
Prosecutor Philip Evans QC suggested that Seed, who had studied electrical engineering and physics at Nottingham University, had possibly brought stolen money to Portugal, where Perkins had a vacation rental in the Algarve.
Seed was identified by the Flying Squad at the end of November 2015, and additional monitoring materials were received at Canary Wharf in April 2016.
The detectives, however, waited until March of last year to strike and caught Seed with more than 1,000 items stolen from the Hatton Garden robbery.
It is believed that he has gradually melted gold and broken jewelry on his bedroom bench, as he was brought from a larger supply in the room.
The Gangexperte Dr. Gordon Burrow compared Seed's hidden footage with Basil's CCTV imagery, dressed in a ginger wig, face mask and hat while carrying a black garbage bag to and from the scene to cover his face in front of the cameras.
The podiatrist told the jury that the "unusual" Hinker provided "strong support" for the charges that Seed Basil was.
The prosecution said electronic devices, including an alarm center and a mobile jammer, found in his home were used for training purposes. He suggested that he wear BT clothing to gain access to the buildings before the crime.
Philip Evans QC said: "In particular, these two offenses required very specialized skills and knowledge to circumvent the alarms and security measures in the premises.
"The prosecution suggests that Mr. Seed is one of those people and has the necessary skills and knowledge to support the successful conduct of these crimes."
Seed claimed that at the time of the Hatton Garden collapse in Cornwall, he had been able to take a family vacation or visit his elderly mother in Cambridge, telling jurors that he had never been known as Basil.
"Everyone calls me Basil now," he said