Police raids on large cannabis farms fell by over 17 per cent last year, it has been revealed.

Sixteen out of 22 police forces, which responded in full to an Freedom of Information request sent by the BBC’s Victoria Derbyshire programme to all 45 police forces in the UK, reported a decrease in farm raids and detections.

Overall there were 651 fewer raids recorded in the last year with numbers falling from 1,038 in 2013/14 to 1,689 in 2014/15.

Significant drops were recorded in four areas including London, where the Metropolitan Police recorded a drop from 203 to 140; Liverpool, where raids fell from 613 to 504; Nottinghamshire which reported a fall of 162 to 124; and Humberside where raids reduced from 53 to 38.

Other areas appeared to follow this pattern according to the BBC.

Cuts in police budgets were cited as a possible cause for the fall in raids.

Bill Jephson, the deputy chief constable of Hertfordshire Police and national lead on cannabis policing for the NPCC, told the BBC that a 25 per cent reduction in police funding in the last five years meant that forces must focus on “key public priorities”.

He added that police forces are now targeting “serious and organised” crime gangs growing cannabis on commercial levels.

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Other causes cited for the fall in raids included gangs moving underground to grow cannabis to avoid police detection by helicopter.

This recent data shows a marked change to the last official figures released from the Association of Chief Police Officers, now named the National Police Chief's Council.

Data from 2008 to 2012 found that raids on commercial cannabis sites more than doubled as organised gangs switched from importing cannabis to growing the drug in large scale operations in the UK.

The NPCC define a commercial cannabis farm as one with at least 25 plants or a farm that makes use of lights and hydroponic equipment.

These latest figures come after Durham police commissioner, Ron Hogg's effective decriminalisation of cannabis in the wake of increasingly limited police resources.