One of the Hatton Garden robbers has won a partial victory at the Court of Appeal against an order to pay back £6 million from the heist.

Michael Seed, known as “Basil”, was jailed for 10 years in March 2019 for his role in the £13.6 million heist.

The alarm specialist was one of two men who climbed into the vault to loot 73 safe deposit boxes after a gang of ageing criminals drilled through the thick concrete wall over the 2015 Easter bank holiday weekend.

In October 2020, Seed, now 60, was ordered to pay back £5,997,684.93 from the raid or serve an extra seven years in jail under a law to confiscate criminals’ ill-gotten gains.

At the Court of Appeal earlier this month, he brought a legal challenge against part of the repayment order covering hundreds of thousands of pounds worth of jewellery.

The court heard that around £4 million in jewellery was stolen in the Hatton Garden raid, with all but around £690,000 worth returned to its owners.

During their confiscation proceedings, Seed’s five co-raiders had agreed that the remaining jewellery – which had either been dismantled or was too generic to be identified – would be sold by police.

His lawyers argued that the judge who made the confiscation order had “overstated” the amount Seed had available to him by including the value of some of the unclaimed jewellery – which had not been in his possession.

In a judgment on Friday, Lord Justice Dingemans granted part of Seed’s appeal.

He said: “The confiscation order against the five men was made on the basis that the jewellery would be sold by the police with the consent of the five men.”

Lord Justice Dingemans, sitting with Mr Justice Soole and Judge Michael Chambers QC, said the confiscation order was overstated by more than £300,000 and should be reduced.

The judge concluded: “The inclusion of the £318,386 as an available amount for Mr Seed in the confiscation order was therefore wrong because it was not available to Mr Seed after the five men had consented to the sale of that jewellery.”

However, he said the order was not overstated in relation to a second set of unclaimed jewellery, with a value of around £66,000.

The seven-year prison sentence, which Seed will have to serve if he does not pay, was also reduced by 136 days.