An invasive weed which can wipe tens of thousands of pounds off the value of a property if found growing in your garden has been discovered on a controversial development site in Kentish Town.

Japanese knotweed is rife across a derelict patch of land known as the railway club at the end of Little Green Street off Highgate Road, where 30 news homes are set to be built.

Several banks refuse to give mortgages on properties where the weed is found growing, such are the damaging effects caused by its roots which are notoriously difficult to eradicate.

The plant is capable of growing through floorboards and brick walls, compromising the foundations of buildings and in some cases leaving no alternative but demolition.

It is estimated that Japanese knotweed can also add up to 10 per cent to the development budget if found on land earmarked for houses due to the cost of treatment.

The news comes just a week after the Ham&High reported hundreds of the weeds growing on public land at the end of Redington Gardens in Hampstead, near some of Hampstead’s most exclusive homes.

The latest discovery of the plant in Kentish Town has fuelled concerns among residents in Little Green Street, who have fought against the development and oppose their historic cobbled road being used to deliver materials for the building work.

Camden Council refused planning permission for the houses but in 2007 developers Euro Investors won an appeal and were given the green light to go ahead with building work, which is thought to begin in the near future.

Residents of Little Green Street are demanding the plants, which are growing through the fence around the site, are removed as soon as possible before it effects their properties.

Liz Payne said: “I’d like it to be got rid of but I know it’s not easy to remove. It has the potential to reduce the value of my house.

“I have no idea if it will delay the construction work but the new owners need to be aware of it and ask questions about whether it’s been removed properly.”

Amanda Blinkhorn said: “The current plan to build houses means nothing else can be done on the site, creating these kinds of problems. It’s just sitting there in limbo, it’s horrible and no-one can use it.”

Satish Patel of PPT Architects London, the firm working on behalf of the site owners, said he was not aware of Japanese knotweed growing at the site but it would be inspected and dealt with.

He said: “If it is found to be the case we will appoint a specialist to give us advice on what to do about it and we will take action.”