Two men posing as window cleaners who broke in and ransacked 23 offices to steal computers and IT equipment are now behind prison window bars.

They had even kept a bucket of dirty water in their van as ‘cover’ if they were ever stopped by police.

Tony Dudley, 40, and Robert Smythe, 54, were each jailed for three years and four months by Southwark Crown Court yesterday.

Dudley, from Horatio Street in Bethnal Green, and his accomplice Smythe, from Dufferin Street in Clerkenwell, admitted at a previous hearing to conspiracy to commit burglary.

The two were eventually stopped in their van in October, when police found hi-visibility jackets, gloves, crowbars, angle-grinders and bolt-croppers which Smythe claimed were “for window cleaning jobs”.

They had a “token” bucket of dirty water and squeegee in the van to back up the ruse.

But detectives suspected they were involved in a string of break-ins. They used a combination of CCTV images of burglaries being committed, vehicle number-plate recognition techniques and Smythe’s DNA which together linked them to 23 break-ins between June and October.

“This was a prolific series of burglaries across London,” Det Con Tony Holley said after the men were jailed.

“Smythe and Dudley were very considered in their criminal activities, operating in a methodical manner by intentionally appearing as legitimate overnight window cleaners, then breaking in calmly and thoroughly ransacking the offices.”

They sometimes used crowbars and other tools to force their way into offices, often using ladders to break in through windows on upper floors.

The IT equipment they stole was worth £70,000, but the damage they caused cost £34,000 on top of that.