(Image: Archant)
The police and Crimestoppers have joined forces to raise awareness of cannabis factories.
Redbridge police have tweeted a number of signs for residents to watch out for.
Cannabis factories may have a strong and sickly sweet smell, constantly covered or blocked off windows, strong lighting all day and night and windows misted up from the heat.
There may also be a constant buzzing or whirring sound, an excessive amount of cables, lighting and ventilation equipment being brought into the house and people coming and going at odd hours.
A spokesman for Redbridge police said residents who suspect there is a cannabis factory in their neighbourhood should call 101 or Crimestoppers anonymously on 0800 555 111.
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