The large haul was discovered on Wednesday after officers conducted three warrants at rented properties on Brecon Close, Sherwood Road and Hatfield Close.

At Brecon Close police recovered 200 cannabis plants, at Sherwood Road 199 plants and at Hatfield Close 571 plants.

The haul is valued at approximately £40,000 and could have produced around £120,000 worth of income each year.

It is understood the three grows found in Rainworth were being tendered to by people of Chinese or Vietnamese origin.

Now officers are warning owners, landlords and managers of rental properties to be aware of common signs of drug cultivation following the large haul.

Said Chief Insp Mark Holland: "This case really demonstrates how important it is for members of the public to call the police immediately if they suspect a property is being used for drug cultivation.

"One resident told officers she had smelt cannabis coming from the property for a year and had never thought to report it to the police."

The haul was uncovered after police received information from an electricity company that the meter at one of the properties had been wired to the underground electricity supply.

Added Chief Insp Holland: "There are huge safety issues around these set-ups, which pose serious dangers and potentially fatal consequences to nearby residents and members of the public.

"The organisers will go to great lengths to supply large amounts of electricity into the property to power the drug cultivation equipment. This is often at great danger to other residents.

"All three properties were being rented by private landlords. Landlords of rental properties have a responsibility to know what is going on within their property.

"We know that criminals involved in drug production often use rental properties in order to distance themselves from illegal activity but this can be at the expense of the local neighbourhood.

"If landlords have any suspicions they should contact us and we will be more than happy to work with them but if they are found to be involved in criminal activity they will be prosecuted."

• Police would like to hear from anybody with further information about these specific properties on 0115 9670999 or Crimestoppers, free and anonymously, on 0800 555 111.