Eight people have been arrested and a ‘vast’ number of car parts seized after a huge police operation.

Around 100 officers from Lancashire Police and West Yorkshire Police executed warrants at Tom Smith Commercials Ltd, on Meadow Street in Great Harwood, and Alf Kymes Ltd, on Blackwood Road in Stacksteads.

Police said both premises are suspected in being involved in the theft of motor vehicles from across the North of England.

They were identified as being the potential location for stolen vehicles to be brought to, where they are alleged to have been broken up in to component parts and sold on.

Three dead horses have also been found at the Great Harwood site and officers are now liaising with the RSPCA.

A 53-year-old man, 38-year-old man, 32-year-old woman, 30-year-old man, and 29-year-old woman all from Great Harwood, and a 50-year-old man and 45-year-old man from Bacup, have all been arrested on suspicion of conspiracy to commit theft, handling stolen goods and money laundering.

A 38-year-old man from Bradford has been arrested on suspicion of conspiracy to commit theft of motor vehicles.

West Yorkshire Police said they have traced stolen vehicles from Leeds, Bradford, Kirklees, Calderdale and Wakefield to Lancashire as part of their intelligence gathering.

Specialist officers from both forces have conducted ‘extensive searches’ of the sites and seized a huge number of nearly new vehicle engines, doors, vehicle panels and other constituent parts, suspected of being from stolen vehicles, mainly from the Yorkshire and Humber area.

Police said the sites ‘present challenges’ and have required the involvement of the Environment Agency and RSPCA working towards enforcement.

A West Yorkshire Police spokesperson said: “The intricacies of accurately identifying vehicle components and attributing them to stolen vehicles has been brought about by the specialist work of police vehicle examiners working with specialists from the automotive industry.

“There has been a continuing trend of keyless vehicle thefts across the Force since 2010, with the 478 Ford Transit Vans vehicles being reported stolen between January 1, 2015 and December 11, 2015 alone, with an estimated value in excess of £7.5m.

“The theft of Ford Transit Vans across the Yorkshire and Humber region accounts for 40 percent of all vehicles stolen, with the make and model being the most stolen vehicle across the UK.”

Chief Superintendent Pat Casserly, of West Yorkshire Police Protective Services Operations, said their ‘planned proactive policing operation’ comes from ‘dedicated’ work by officers in both Lancashire and West Yorkshire.

He said: “Operations like the one this week demonstrate our ongoing commitment to tackling this issue.“The scale and organisation of the sites have been quite remarkable as this appears to be a well organised, systematic and efficient process to deconstruct vehicles, categorise them and move them on for sale.“Whilst collectively these incidents result in high value crime, we must remember that each theft has very human consequences.

“These types of vehicles are often owned and utilised by small businesses and for some, the theft of a vehicle can result in the loss of contracts and future work. Proactive operations such as these help prevent other vehicle owners from potentially becoming future victims of crime.“Criminals often have the misconception that travelling across county borders makes their crimes more difficult to detect and investigate.

“Whilst this can provide challenges to investigators, it by no means prevents officers dedicating themselves to locating those who commit offences, investigating their crimes and bringing them to justice.

“This week’s operation highlights that Forces are continuing to work closely together to tackle and deal with these challenges in order to detect crime, and protect the vulnerable.”