THIEVES struck three times to steal 23,000 litres of diesel worth £25,000 from a Darwen transport depot.
Police said CCTV footage shows the assailants enter Nightfreight in Lower Eccleshill Road via the adjoining Canopies premises.
They first arrived on a Saturday night, at about 10.30pm, returning twice the following afternoon.
At about 1pm on Sunday, September 30, a white lorry, similar in looks to a chilled unit, was captured on CCTV in the compound for about 90 minutes before leaving.
The thieves were seen using black piping to pump diesel out of the fuel tank to the waiting vehicles and possibly into plastic containers.
The lorry then left the yard and a second lorry then entered the yard and the process was repeated.
Police said they believed the offenders were either ill-prepared for the theft on the Saturday or were making initial preparations to steal the fuel.
DC Dan Perkins from Blackburn CID said police were appealing for information over the theft.
He said: “I’d be very interested to hear from anybody who may be able to identify either lorry.
“I’d also like to hear from any operators who may have had similar vehicles stolen and recovered that smelled of diesel.
“Fuel was spilt over a large distance on the roads close to the theft site, indicating that the thieves weren’t too careful while filling the containers in the lorries so the load areas may have had to have been cleaned substantially.”
The first lorry was described as a white rigid side, rear door lorry. It had an aerofoil on the cab and was possibly an Iveco unit.
The second lorry was a white cabbed, blue curtain sided rigid lorry with rear curtain sides.
Anyone with information can call DC Perkins on 01254 353564 or Lancashire Police on 101.
People with information can also contact Crimestoppers anonymously on 0800 555111.