Thieves, posing as rail workers, raided a Stratford rail depot and stole tools, worth thousands of pounds, needed for the huge upgrade of the London Tube network, it is revealed.

Some of the gang wore hi-vis jackets and safety helmets to disguise themselves as official workers. The at least six-strong gang broke into a plant compound close to the station of a construction contractor and robbed it of “a large amount of tools”.

Police investigations forced the suspension of work, part of the multi-billion pound regeneration of the London Underground aimed towards a “world class” transport service by next summer to cope with the tens of thousands of visitors to Stratford’s Olympic Park,

The break-in also saw �3,000 worth of damage caused to the depot.

British Transport Police investigators have released CCTV of the men they want the public’s help to identify.

The raid took place in the early hours of Monday, October 10.

Det Con Graeme Knox, of BTP’s Criminal Investigation Department based at Stratford, said it is believed the disguised thieves broke into the compound between 5.30 and 6am.

He said: “During the burglary a large amount of tools, essential to the work being carried out at the site, were taken and operations were forced to cease while a police investigation was launched.

“The break-in also saw over �3,000 worth of damage caused to the site, including broken windows and vandalised door-locks.

The officer admitted the raid was “clearly a well-organised and premeditated burglary” and

asked for public assistance.

Anyone with information is asked to contact British Transport Police on 0800 40 50 40 quoting B11/LNA of 01/11/2011. Information can also be given anonymously to the independent charity Crimestoppers on 0800 555 111.