AFTER seizing a bumper crop of cannabis, detectives were making the most of their triumph.
They boasted about the £300,000 capture in a blaze of publicity and posed for photos with some of the 1,000 plants in the haul.
An officer from South Wales Police poses with the £300,000 cannabis haul. As police stood guard at the front of the cannabis factory, thieves broke in through the back and stole some of the drugs
They broke in and started stuffing the cannabis into black bin bags to be loaded into a waiting van.
A neighbour, who was clearly somewhat more vigilant than the officers on the scene, noticed what was happening and raised the alarm.
But, by then, an estimated £15,000 of cannabis plants had been stolen.
An insider at South Wales Police said: ‘There are a few red faces around.
‘Everyone was chuffed with busting the huge factory and there was a blaze of publicity about it.
‘There was such a lot of cannabis inside we had to bring in council experts to dispose of it.
‘While we were waiting for that to happen, the thieves broke in through the back.’
Officers were carrying out an investigation nearby when they got a whiff of the secret factory and followed their noses to a disused nightclub at Merthyr Tydfil, South Wales
Police uncovered the massive drugs farm by chance in a former nightclub at Merthyr Tydfil.
Officers were carrying out an investigation nearby when they got a whiff of the drugs and followed the scent to the disused building.
They burst in and found more than 1,000 plants under a sophisticated hydroponic lighting and irrigation system.
The plantation was so large that council waste experts were called in to dispose of the lucrative crop. To guard the seizure until they arrived, two Police Community Support Officers were told to keep watch at the front of the building.
But the rear of the old nightclub was left unguarded, leaving the thieves free to break in and grab a van full of the plants.
Yesterday South Wales Police said it had started an internal investigation into the blunder to find out if ‘scene preservation protocols’ were followed.
The insider added: ‘There should have been a team of officers tasked to guard the building’s front and back until the cannabis was cleared out of there.’
Four Vietnamese men, aged 26 to 48, are in custody charged with jointly producing cannabis.
The seizure came as dope farming has reached a record high, with the number of seized plants soaring by nearly 20 per cent last year.
The Home Office said 758,700 plants were seized across the country, compared with 643,510 between 2008 and 2009.
Most hauls were at small drug factories, with four out of five seizures for 50 plants or fewer.
But in one raid last year, police uncovered £250,000 worth of cannabis plants in a seven- bedroomed £1million mansion in a Birmingham neighbourhood nicknamed Millionaires’ Row.
Last year insurance companies also paid out a record number of claims to landlords who unknowingly had their properties turned into illegal cannabis farms.
Aviva reported payouts to 92 landlords, a rise of 30 per cent on the previous year.
Dope farms are generally found in empty rented properties with blacked-out windows to aid cultivation, said the Association of Chief Police Officers.