CANNABIS farms set up in the city by organised criminals to are producing some of the strongest strains of the drug in the country.
The Association of Chief Police Officers (ACPO) found that West Yorkshire tops the league for cannabis cultivation.
In the last 12 months 253 farms were found in Wakefield alone.
Average strains of the class B drug produced in the city are around six per cent stronger than the national average, according the West Yorkshire Police force drugs co-ordinator Bryan Dent.
He said: “In West Yorkshire the tetrahydrocannabinol (THC) content, which is the active chemical in cannabis, is around 22 per cent.
“Nationally the strength is around 16 per cent. That means that in Wakefield the cannabis that is being consumed and sold is actually stronger than the national average.
“And that fuels the debate about how safe it is and the impact on mental health.”
The report focused on commercial cannabis farms which contain more than 25 plants.
Mr Dent said there was a clear link in Wakefield between large scale farms and organised crime, but the criminal’s growing tactics had changed.
He said: “There was a time, two or three years ago, when a lot of cannabis farms were set up in commercial premises, factories and industrial units.
“The trend now seems to be domestic set-ups in bedrooms as opposed to houses full.
“We think the growers think there might be bigger chance of getting away with it.”
Police have urged people to be on the look out for tell tale signs of cannabis farms.
They include a distinctive, strong, sweet smell coming from houses and drawn curtains or blacked out windows.
People may be seen visiting the house at strange hours or might be seen carrying bags of fertiliser or other equipment into the house.
To contact police call 101 or Crimestoppers on 0800 555111.