The Met Police found double the number of cannabis farms during the first year of lockdown, according to a new report.
Officers raided 455 farms in the capital in 2020, which was around half of the 1,096 discovered from November 2015 to December 2021, the data showed.
The figure for 2020, when the UK COVID restrictions began, was more than double of any of the four previous years.
The Met released the data to Conservative London Assembly member and former mayoral candidate Shaun Bailey, the BBC reported.
A spokesman for the Mayor of London said the statistics showed police were "bearing down on illegal drugs".
He said: "This is a vital part of their work to reduce the harm and violence drugs and drug-related crimes cause to individuals, families and communities.
"Cannabis farms drive up levels of drug dealing in our city, which often involves the exploitation of young vulnerable Londoners, and closing these farms down is a key part of the fight against modern slavery."
London mayor Sadiq Khan has announced plans for a pilot to “decriminalise” cannabis offences for people under 24.
A spokesperson added: “This limited trial, which is still in development and has yet to be approved by City Hall, would involve three of London’s 32 boroughs and would only apply to 18-24 year olds found in possession of a small amount of cannabis. It would not apply to any other drug.
“The idea of the scheme, which is already used by other police forces across the country, would be to divert young people who are found with a small amount of cannabis away from the criminal justice system and instead provide help and support. This has been shown to reduce reoffending.
“Reducing crime is the Mayor’s top priority and he will continue to explore and implement the most effective solutions to help to divert young people away from drug use and crime for good.”
In December, more than 1000 cannabis plants, with an estimated street value of £1 million and cultivation equipment were seized by officers and removed from the venue in Rainham, east London.
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