The mastermind behind a multi-million pound jewellery heist described as Britain’s largest burglary in legal history is allegedly in intensive care.

Brian Reader, the “guv’nor” of the Hatton Garden raid and a pensioner from Dartford has allegedly been moved from Belmarsh Prison in Woolwich where he was awaiting sentence to a local hospital.

The Queen Elizabeth Hospital reportedly confirmed he is a critical condition in their intensive care unit (ICU).

He faces a maximum 10-year spell behind bars, although he is entitled to a reduction on account of his guilty plea.

In January The Sun published a picture of Reader leaving a hospital after cancer treatment and other news sources today have reported he is in intensive care unit (ICU) at Queen Elizabeth Hospital, in a critical condition.

Reader, 76, has been threatened with being stripped of his assets, including his luxurious £1million home in Dartford Road.

He headed a gang of men responsible for stealing a haul worth at least £14 million of jewels, gold and cash from London’s famous jewellery quarter and the centre of the UK diamond trade.

It took them three years to plan the raid and the ringleaders watched YouTube videos of how to use powerful concrete piercing drills.

Posing as gas repairmen, the gang, one of whom has not been traced, gained access to the building before boring a hole through a thick concrete wall and breaking into a vault over the Easter weekend last year.

Their crime was almost scuppered when they triggered a burglar alarm. This alerted the Metropolitan Police but it was given a grade which meant it required no response, so the raiders carried on regardless.

Only around a third of the haul has been recovered after the gang ransacked 73 safety deposit boxes.

Reader pleaded guilty to conspiracy to burgle with intent to steal ahead of a two-month trial at Woolwich Crown Court of several of his accomplices.

He is due to be sentenced next month but additional time could be added on if the gang does not reveal the whereabouts of the missing loot.

A prison service spokeswoman said: "An HMP Belmarsh prisoner was taken to hospital on 24 February. He remains there in order to receive treatment for an ongoing medical condition.

"Appropriate security measures are in place."