Police have seized £1 million of cannabis after finding plants growing on the top floor of a building.

The Metropolitan Police said officers from its territorial support group were called to an address on the North Circular Road, NW2, on Tuesday by concerned members of the public.

Once inside they saw a staircase had been barricaded, with officers and a police dog then working their way through the building until they found a large amount of cannabis plants growing.

Taskforce’s chief inspector Grace Blake-Turner said the plants, which have an estimated value of approximately £1 million, were "evidentially being grown with the sole intention to be sold for a vast amount of profit".

She added: "I’d like to thank the members of public who alerted us to this address. Because they voiced their concerns to police, over £1 million worth of class B drugs are now off the streets."

North-west BCU commander Louis Smith said: "Growing and selling cannabis funds career criminals who cause misery to others and commit acts of extreme violence.

"People are killed in producing cannabis in this way. These criminals also often prey upon the extremely vulnerable, for example by forcing them to manage cannabis farms."

An investigation is under way to find those responsible for the growing and selling of the drugs.