The Metropolitan Police are investigating claims that another £7 million worth of gold was stolen during the Hatton Garden raid over Easter in 2015.
According to a BBC report, a woman has said she only realised her safety deposit box was missing following the trial of the gang who carried out the raid in London’s jewellery quarter.
If true, this would mean the total taken during the theft would be about £21 million.
Seven men were jailed last year in what many have described as the “largest burglary in English legal history”.
The Metropolitan Police confirmed in a statement that they were notified of a “further allegation” in February, after the trial of the gang had ended.
The Hatton Garden raid was already known to be Britain’s biggest ever burglary. The gang bored into the vault of Hatton Garden Safe Deposit Ltd, which is now defunct.
About two thirds of the valuable have not yet been recovered.
The report, first published by Sky News, could mean that those already convicted of the raid could receive extensions on their jail sentences, if it is found to be true.