A woman has come forward after realising £7m of her gold is missing nearly two years after a heist at a London safety deposit box company.

The woman claimed one of her safety deposit boxes had been stolen and she only realised it was missing after the trial of the gang who carried out the April 2015 raid.

The claim, which is being treated seriously by police, would mean the total stolen in the heist stands at around £21m, Sky's Crime Correspondent Martin Brunt said.

Image: John Collins, Daniel Jones, Terry Perkins, (bottom row left to right) Carl Wood, William Lincoln and Hugh Doyle

Seven men were convicted in March last year over the break-in at Hatton Garden Safe Deposit in London and jailed for terms of six and seven years.

:: The biggest heists in UK history


The gang ransacked 73 safe deposit boxes after using a drill to bore a hole into the vault wall during the meticulously-planned heist, taking gold, diamonds and sapphires.

The raid, carried out over the Easter bank holiday weekend in the heart of London's diamond district, was the biggest burglary in English history.

Image: Brian Reader, 77, the oldest man convicted in the Hatton Garden raid

Ringleaders John "Kenny" Collins, 75; Daniel Jones, 61, and Terry Perkins, 67, were sentenced to seven years and Brian Reader, 77, was jailed for six years and three months.

Carl Wood was jailed for six years and William Lincoln for seven after they were convicted of conspiracy to commit burglary and conspiracy to conceal, convert of transfer criminal property.

Plumber Hugh Doyle, 48, was convicted of laundering the stolen goods after he let the gang use his workshop forecourt to transfer bags of jewellery between vehicles. He was sentenced to 21 months, suspended for two years.

Image: The inside of the vault at the Hatton Garden Safe Deposit company

The majority of the jewellery and gold stolen has not been recovered.

Confiscation hearings for the gang members have been held up because it has not been possible to agree what is still missing from the raid.

The gang members face longer sentences if the stolen goods are not returned.

A statement from the Metropolitan Police said: "In June 2016, police received an allegation of theft from a security box relating to the Hatton Garden burglary in April, 2015.

"The victim is alleging the loss of a substantial amount of property. The investigation is ongoing."